METHOD FOR PREPARING NANO-TITANATE, NANO-TITANIC ACID AND NANO-TIO2 CONTAINING EMBEDDED NANOPARTICLES AND METHOD FOR PREPARING METAL NANOPARTICLES

Abstract

A method for preparing a nano-titanate, a nano-titanic acid and a nano-TiO.sub.2 containing embedded A nanoparticles is provided respectively. In this method, a Ti-T alloy with a A-group element solidly dissolved therein is used as a titanium source, and reacted with an alkali solution under a certain condition. In combination with subsequent treatment, the preparation of a titanate nanotube, a titanic acid nanotube, and a TiO.sub.2 nanotube/rod containing embedded A nanoparticles, respectively, is further achieved with high efficiency and low cost. Moreover, a method for preparing metal nanoparticles is also provided by removing the matrix of the composites. The present preparation methods is characterized by simple process, easy operation, high efficiency, low cost. The product is of promising application in polymer-based nanocomposites, ceramic materials, catalytic materials, photocatalytic materials, hydrophobic materials, effluent degrading materials, bactericidal coatings, anticorrosive coatings, marine coatings.

Claims

1. A method of preparing a titanate nanofilm material containing embedded A nanoparticles, comprising: step (1) providing an initial alloy; wherein the initial alloy comprises a T-type element, Ti and a A-group element, and the phase composition of the initial alloy mainly consists of a T-Ti intermetallic compound solidly dissolved with the A-group element; and the T-type element comprises at least one of Al and Zn, the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and when the A-group element comprises Ag, the atomic percentage content of Ag in the A-group element is less than 50%; step (2) reacting the initial alloy with an alkali solution at a temperature of T.sub.1, during which a reaction interface advances inward from the surface of the initial alloy at an average rate of greater than 2 ?m/min; and the initial alloy at the reaction interface undergoes nano-fragmentation through a hydrogen generation and T-removal reaction and simultaneously undergoes shape and composition reconfiguration to generate a solid flocculent product containing embedded A nanoparticles; wherein T.sub.1?60? C.; and step (3) lowering the temperature of the solid flocculent product containing embedded A nanoparticles in the reaction system in the step (2) from T.sub.1 and collecting the solid flocculent product containing embedded A nanoparticles, i.e., obtaining the titanate nanofilm material containing embedded A nanoparticles; wherein the A nanoparticles comprise at least one of A nanoparticles and A-O nanoparticles.

2. A method of preparing a titanic acid nanofilm material containing embedded A nanoparticles, comprising: reacting the product prepared according to claim 1 or the titanate nanofilm material containing embedded A nanoparticles prepared according to claim 1 with an acid solution, and collecting the solid product, i.e., obtaining the titanic acid nanofilm material containing embedded A nanoparticles.

3. A method of preparing a TiO.sub.2 nanosheet powder containing embedded A nanoparticles, comprising: heating the as-prepared product prepared according to claim 2 or the titanic acid nanofilm material containing embedded A nanoparticles prepared by the method according to claim 2 to obtain the TiO.sub.2 nanosheet powder containing embedded A nanoparticles.

4. A method of preparing titanate nanotubes containing embedded A nanoparticles, comprising the following steps: sealing a solid substance with a alkaline solution in a closed vessel, wherein the solid substance is the product or the titanate nanofilm containing embedded A nanoparticles prepared according to claim 1, then the solid substance and the alkaline solution in the closed vessel were treated by a high pressure and a high temperature of T.sub.2 which is higher than that of the T.sub.f solution; wherein the T.sub.f solution is the boiling temperature of the alkali solution involved in the reaction at ambient pressure, and T.sub.1<T.sub.f solution<T.sub.2; after a certain time of reaction, the temperature of the closed vessel is reduced and the pressure is restored to ambient pressure, and the final solid product is collected, i.e., the titanate nanotubes containing embedded A nanoparticles are obtained; wherein, the A nanoparticles comprises at least one of A nanoparticles and A-O nanoparticles.

5. A method of preparing a titanic acid nanotube material containing embedded A nanoparticles, comprising: reacting the product prepared according to claim 4 or the titanate nanotube material containing embedded A nanoparticles prepared according to claim 4 with an acid solution, and collecting the solid product, i.e., obtaining the titanic acid nanotube material containing embedded A nanoparticles.

6. A method of preparing a TiO.sub.2 nanotube/rod containing embedded A nanoparticles, comprising: heating the as-prepared product according to claim 5 or the titanic acid nanotube containing embedded A nanoparticles prepared by the method according to claim 5 to obtain the TiO.sub.2 nanotubes/rods containing embedded A nanoparticles.

7. A method of preparing a titanate nanotube containing embedded A nanoparticles, comprising: step 1), providing an initial alloy comprising T-type elements, Ti and A-group element; and the phase composition of the initial alloy comprises a T-Ti intermetallic compound with solid dissolved A-group elements; wherein the T-type elements comprise at least one of Al and Zn; the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and when the A-group element contains Ag, the atomic percentage content of Ag in A is less than 50%; step 2), sealing the initial alloy with the alkaline solution in a closed vessel, and subsequently heating the closed reaction system to the temperature of T.sub.2 and holding it for a certain period of time; wherein 100? C.<T.sub.f solution<T.sub.2; T.sub.f solution is the boiling point temperature of the alkaline solution involved in the reaction at ambient pressure, and the pressure in the reaction vessel at the temperature of T.sub.2 is higher than the ambient pressure; step 3), lowering the temperature of the closed vessel and restoring the pressure to ambient pressure, and collecting the final solid product, i.e., obtaining the titanate nanotubes containing embedded A nanoparticles; wherein the A nanoparticles comprise at least one of A nanoparticles and A-O nanoparticles.

8. A method of preparing a titanic acid nanotube containing embedded A nanoparticles, comprising: reacting the product prepared according to claim 7 or the titanate nanotube material containing embedded A nanoparticles prepared according to claim 7 with an acid solution, and collecting the solid product, i.e., obtaining the titanic acid nanotube material containing embedded A nanoparticles.

9. A method of preparing a TiO.sub.2 nanotube/rod containing embedded A nanoparticles, comprising: heating the as-prepared product according to claim 8 or the titanic acid nanotube prepared by the method according to claim 8 to obtain the TiO.sub.2 nanotubes/rods containing embedded A nanoparticles.

10. A titanate nanofilm material containing embedded A nanoparticles, wherein the titanate nanofilm material containing embedded A nanoparticles is prepared by the method according to claim 1, comprising the following features: the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and when the A-group element contains Ag, the atomic percentage content of Ag in A is less than 50%; the A nanoparticles comprise at least one of A nanoparticles and A-O nanoparticles; the particle size of the A nanoparticles is 1.0 nm?30 nm; the A nanoparticles are present in the titanate nanofilm mainly by means of embeddness; the titanate nanofilm containing embedded A nanoparticles has a thickness of 0.25 nm?7 nm; the titanate nanofilm containing embedded A nanoparticles has an average area of greater than 500 nm.sup.2; and in the titanate nanofilm containing embedded A nanoparticles, the molar ratio of the A-group element to Ti satisfies 0<C.sub.A/C.sub.Ti?0.30.

11. A titanic acid nanofilm material containing embedded A nanoparticles, wherein the titanic acid nanofilm material containing embedded A nanoparticles is prepared by the method according to claim 2, comprising the following features: the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and when the A-group element contains Ag, the atomic percentage content of Ag in A is less than 50%; the A nanoparticles comprise at least one of A nanoparticles and A-O nanoparticles; the particle size of the A nanoparticles is 1.0 nm?30 nm; the A nanoparticles are present in the titanic acid nanofilm mainly by means of embeddness; the titanic acid nanofilm containing embedded A nanoparticles has a thickness of 0.25 nm?7 nm; the titanic acid nanofilm containing embedded A nanoparticles has an average area of greater than 500 nm.sup.2; and in the titanic acid nanofilm containing embedded A nanoparticles, the molar ratio of the A-group element to Ti satisfies 0<C.sub.A/C.sub.Ti?0.30.

12. A TiO.sub.2 nanosheet powder containing embedded A nanoparticles, wherein the TiO.sub.2 nanosheet powder containing embedded A nanoparticles is prepared by the method according to claim 3, comprising the following features: the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and when the A-group element contains Ag, the atomic percentage content of Ag in A is less than 50%; the A nanoparticles comprise at least one of A nanoparticles and A-O nanoparticles; the particle size of the A nanoparticles is 1.0 nm?100 nm; the A nanoparticles are present in the TiO.sub.2 nanosheet mainly by means of embeddness; the TiO.sub.2 nanosheet containing embedded A nanoparticles has a thickness of 1 nm?40 nm; the TiO.sub.2 nanosheet containing embedded A nanoparticles has an average area of greater than 100 nm.sup.2; the TiO.sub.2 nanosheet containing embedded A nanoparticles has shape of sheet; the phase composition of the nano-TiO.sub.2 in the TiO.sub.2 nanosheet powder containing embedded A nanoparticles includes at least one of brookite-type TiO.sub.2, anatase-type TiO.sub.2, and rutile-type TiO.sub.2; and in the TiO.sub.2 nanosheet containing embedded A nanoparticles, the molar ratio of the A-group element to Ti satisfies 0<C.sub.A/C.sub.Ti?0.30.

13. A titanate nanotube containing embedded A nanoparticles, wherein the titanate nanotube containing embedded A nanoparticles is prepared by the method according to claim 4, comprising the following features: the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and when the A-group element contains Ag, the atomic percentage content of Ag in A is less than 50%; the A nanoparticles comprise at least one of A nanoparticles and A-O nanoparticles; the particle size of the A nanoparticles is 1.0 nm?40 nm; the A nanoparticles are present in the titanate nanotube mainly by means of embeddness; the titanate nanotube containing embedded A nanoparticles has has an outer diameter of 2.0 nm?25 nm; the titanate nanotube containing embedded A nanoparticles has an average length of greater than 5 times their average outer diameter; and in the titanate nanotube containing embedded A nanoparticles, the molar ratio of the A-group element to Ti satisfies 0<C.sub.A/C.sub.Ti?0.30.

14. A titanic acid nanotube containing embedded A nanoparticles, wherein the titanic acid nanotube containing embedded A nanoparticles is prepared by the method according to claim 5, comprising the following features: the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and when the A-group element contains Ag, the atomic percentage content of Ag in A is less than 50%; the A nanoparticles comprise at least one of A nanoparticles and A-O nanoparticles; the particle size of the A nanoparticles is 1.0 nm?40 nm; the A nanoparticles are present in the titanic acid nanotube mainly by means of embeddness; the titanic acid nanotube containing embedded A nanoparticles has an outer diameter of 2.025 nm; the titanic acid nanotube containing embedded A nanoparticles has an average length of greater than 5 times their average outer diameter; and in the titanic acid nanotube containing embedded A nanoparticles, the molar ratio of the A-group element to Ti satisfies 0<C.sub.A/C.sub.Ti?0.30.

15. A TiO.sub.2 nanotube/rod containing embedded A nanoparticles, wherein the TiO.sub.2 nanotube/rod containing embedded A nanoparticles is prepared by the method according to claim 6, comprising the following features: the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and when the A-group element contains Ag, the atomic percentage content of Ag in A is less than 50%; the A nanoparticles comprise at least one of A nanoparticles and A-O nanoparticles; the particle size of the A nanoparticles is 1.0 nm?100 nm; the A nanoparticles are present in the TiO.sub.2 nanotube/rod mainly by means of embeddness; the TiO.sub.2 nanotube/rod containing embedded A nanoparticles has an outer diameter of 2.0 nm?25 nm; the TiO.sub.2 nanotube/rod containing embedded A nanoparticles has an average length of greater than 3 times their average outer diameter; the phase composition of the nano-TiO.sub.2 in the TiO.sub.2 nanotube/rod containing embedded A nanoparticles includes at least one of brookite-type TiO.sub.2, anatase-type TiO.sub.2, and rutile-type TiO.sub.2; and in the TiO.sub.2 nanotube/rod containing embedded A nanoparticles, the molar ratio of the A-group element to Ti satisfies 0<C.sub.A/C.sub.Ti?0.30.

16. A titanate nanotube containing embedded A nanoparticles, wherein the titanate nanotube containing embedded A nanoparticles is prepared by the method according to claim 7, comprising the following features: the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and when the A-group element contains Ag, the atomic percentage content of Ag in A is less than 50%; the A nanoparticles comprise at least one of A nanoparticles and A-O nanoparticles; the particle size of the A nanoparticles is 1.0 nm?35 nm; the A nanoparticles are present in the titanate nanotube mainly by means of embeddness; the titanate nanotube containing embedded A nanoparticles has has an outer diameter of 2.0 nm?25 nm; the titanate nanotube containing embedded A nanoparticles has an average length of greater than 5 times their average outer diameter; and in the titanate nanotube containing embedded A nanoparticles, the molar ratio of the A-group element to Ti satisfies 0<C.sub.A/C.sub.Ti?0.30.

17. A titanic acid nanotube containing embedded A nanoparticles, wherein the titanic acid nanotube containing embedded A nanoparticles is prepared by the method according to claim 8, comprising the following features: the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and when the A-group element contains Ag, the atomic percentage content of Ag in A is less than 50%; the A nanoparticles comprise at least one of A nanoparticles and A-O nanoparticles; the particle size of the A nanoparticles is 1.0 nm?35 nm; the A nanoparticles are present in the titanic acid nanotube mainly by means of embeddness; the titanic acid nanotube containing embedded A nanoparticles has an outer diameter of 2.0 nm?25 nm; the titanic acid nanotube containing embedded A nanoparticles has an average length of greater than 5 times their average outer diameter; and in the titanic acid nanotube containing embedded A nanoparticles, the molar ratio of the A-group element to Ti satisfies 0<C.sub.A/C.sub.Ti?0.30.

18. A nano-TiO.sub.2 nanotube/rod containing embedded A nanoparticles, wherein the nano-TiO.sub.2 nanotube/rod containing embedded A nanoparticles is prepared by the method according to claim 9, comprising the following features: the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and when the A-group element contains Ag, the atomic percentage content of Ag in A is less than 50%; the A nanoparticles comprise at least one of A nanoparticles and A-O nanoparticles; the particle size of the A nanoparticles is 1.0 nm?100 nm; the A nanoparticles are present in the TiO.sub.2 nanotube/rod mainly by means of embeddness; the TiO.sub.2 nanotube/rod containing embedded A nanoparticles has an outer diameter of 2.0 nm?25 nm; the TiO.sub.2 nanotube/rod containing embedded A nanoparticles has an average length of greater than 3 times their average outer diameter; the phase composition of the nano-TiO.sub.2 in the TiO.sub.2 nanotube/rod containing embedded A nanoparticles includes at least one of brookite-type TiO.sub.2, anatase-type TiO.sub.2, and rutile-type TiO.sub.2; and in the TiO.sub.2 nanotube/rod containing embedded A nanoparticles, the molar ratio of the A-group element to Ti satisfies 0<C.sub.A/C.sub.Ti?0.30.

19. An application of the product material prepared by the method according to any one of claim 1-9, or the material according to any one of claim 10-18, in polymer-based nanocomposites, ceramic materials, catalytic materials, photocatalytic materials, hydrophobic materials, effluent degrading materials, bactericidal coatings, anticorrosive coatings, marine coatings.

20. A method of preparing metal nanoparticles, comprising: reacting a material prepared by the method described in any one of claims 1, 2, 4, 5, 7 and 8, or the material described in any one of claims 10, 11, 13, 14, 16 and 17, with an acid solution to remove the matrix which the A nanoparticles are embedded and attached, thereby obtaining freely dispersible A nanoparticles; wherein the A nanoparticles are mainly nanoparticles composed of A-group element.

21. The method of preparing metal nanoparticles according to claim 20, wherein the A nanoparticles are mainly composed of A-group element, and the the A-group element comprises at least one of Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, Ni, Fe and Co, and the atomic percentage content of Au, Pt, Pd, Ru, Rh, Os, Ir, and Ag in A is more than 40%, and when the A-group element contains Ag, the atomic percentage content of Ag in A is less than 50%;

22. The method of preparing metal nanoparticles according to claim 20, wherein the particle size of the A nanoparticles is 1.5 nm?250 nm.

23. An application of the product material prepared by the method according to any one of claims 1-9, or the material according to any one of claims 10-18, in home decoration paint, germicidal spray, or antifouling paint; wherein the composition of the A nanoparticles in the product material or material comprises at least one of Cu, Ag; when used as the home decoration paint, the material comprises at least one of Cu, Ag is used as a paint additive and mixed with other components to be applied to a surface of a furniture, an artifact, or a wall to achieve an antibacterial effect; when used as the germicidal spray, the material comprises at least one of Cu, Ag is mixed with other liquid spray components and sprayed onto a surface of furniture, utensils, fabrics, and walls through a carrier to achieve antibacterial effect; when used as the antifouling paint, the material comprises at least one of Cu, Ag is used to replace the sterilizing and antifouling component in a traditional antifouling paint to achieve antifouling effect.

24. An application of the product material prepared by the method according to any one of claims 1-9, or the material according to any one of claims 10-18, in antibacterial fabric, wherein the composition of the A nanoparticles in the product material or material comprises at least one of Cu, Ag; and the Cu or (and) Ag-containing product materials or materials are dispersed so as to be attached to or coated on the surface of the fabric or mixed with the fabric, so as to achieve an antimicrobial and antiseptic effect and capability for the fabric.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0631] FIG. 1 shows the low-magnification and high-magnification transmission electron microscope (TEM) photographs of a titanic acid nanofilm containing embedded Au nanoparticles in Embodiment 1;

[0632] FIG. 2 shows the TEM photograph of the anatase TiO.sub.2 nanosheets containing embedded Au nanoparticles in Embodiment;

[0633] FIG. 3 shows the TEM photograph of a mixed product of a titanic acid nanofilm containing embedded Au nanoparticles and anatase TiO.sub.2 nanosheets containing embedded Au nanoparticles in Embodiment 2;

[0634] FIG. 4 shows the low-magnification, mid-magnification and high-magnification TEM photographs of a titanic acid nanofilm containing embedded Au(Cu) nanoparticles in Embodiment 3;

[0635] FIG. 5 shows an X-ray diffraction (XRD) spectrum of the titanic acid nanofilm containing embedded Au(Cu) nanoparticles in Embodiment 3;

[0636] FIG. 6 shows the TEM photograph of Au(Cu) nanoparticles in Embodiment 3;

[0637] FIG. 7 shows the TEM photograph of Au nanoparticles in Embodiment 3;

[0638] FIG. 8 shows the TEM photograph of a titanic acid nanofilm containing embedded CuO nanoparticles in Embodiment 4;

[0639] FIG. 9 shows an XRD spectrum of the titanic acid nanofilm containing embedded CuO nanoparticles in Embodiment 4;

[0640] FIG. 10 shows the TEM photograph of a titanic acid nanofilm containing embedded AuPdPtCuAg nanoparticles in Embodiment 5;

[0641] FIG. 11 shows an XRD spectrum of the product in Comparative Example 1;

[0642] FIG. 12 shows an XRD spectrum of an anatase TiO.sub.2 powder before reacting in Comparative Example 1;

[0643] FIG. 13 shows a low-magnification SEM photograph of the product in Comparative Example 2;

[0644] FIG. 14 show a high-magnification SEM photograph of the product in Comparative Example 2;

DETAILED DESCRIPTION OF EMBODIMENTS

[0645] Hereinafter, the described technical solutions will be further illustrated by the following specific embodiments:

Embodiment 1

[0646] The embodiment provided a method of preparing a two-dimensional sodium titanate nanofilm material containing embedded Au nanoparticles, a two-dimensional titanic acid nanofilm material containing embedded Au nanoparticles, and a TiO.sub.2 nanosheet powder containing embedded Au nanoparticles and an application thereof, including the following steps.

[0647] Weighing the metal Au, Ti and Al raw materials according to the ratio of Au.sub.1.5Ti.sub.24.5Al.sub.74 (atomic percentage), melting to obtain an alloy melt with the composition of Au.sub.1.5Ti.sub.24.5Al.sub.74; preparing the alloy melt into an initial alloy in the form of ribbons with a thickness of ?25 ?m by a rapid solidification method using melt spinning with copper roller. The initial alloy is mainly composed of TiAl.sub.3 intermetallic compounds containing solid dissolved Au.

[0648] Under atmospheric pressure, 0.25 g of the above-made Au.sub.1.5Ti.sub.24.5Al.sub.74 initial alloy ribbon was added into 50 ml of aqueous NaOH solution at a concentration of 10 mol/L and a temperature of its boiling point (about 119? C.) with constant stirring. During the reaction with the concentrated alkaline solution, the Au.sub.1.5Ti.sub.24.5Al.sub.74 initial alloy ribbon undergoes nano-fragmentation through intense hydrogen generation and Al-removal reaction, and simultaneously undergoes shape and compositional reconfiguration to produce solid flocculent products diffusely distributed in the alkaline solution.

[0649] The hydrogen generation and Al-removal reaction was finished within 10 s, and the temperature was hold for 1 min to ensure the completion of the reaction, and then 450 ml of room temperature water was rapidly poured into the reaction system under stirring, and the concentration of alkali in the solution was reduced to 1 mol/L within 2 s, and the temperature was reduced to below 45? C.

[0650] The solid flocculent product was separated from the alkaline solution, cleaned, and dried, i.e., sodium titanate nanofilm material with embedded Au nanoparticles was obtained, with the thickness of a single film ranging from 0.25 nm to 5 nm, and the average area of the film was larger than 2000 nm.sup.2, and the particle size of the embedded Au nanoparticles was 1.0?10 nm.

[0651] The solid flocculent product after separation from the alkaline solution as described above was dispersed in water, and then 0.025 mol/L HCl solution was gradually added to it, so that the pH value of the mixed solution was continuously decreased, and the pH value of the mixed solution was finally controlled between 2 and 5. After 5 min, the solid-liquid separation was carried out, and after being cleaned and dried i.e., titanic acid nanofilm material with embedded Au nanoparticles was obtained. The thickness of the single film was about 0.25 nm?5 nm, and the average area of the film was larger than 2000 nm.sup.2. The TEM morphology was shown in the low magnification and high magnification photographs of FIG. 1. The Au nanoparticles were embedded in the titanic acid nanofilm. If they existed through adsorption, there would be some single discrete Au nanoparticles separated from the titanate nanofilm in a TEM observation field. Since the diameter of some embedded Au nanoparticles was larger than the thickness of the nanofilm matrix, some Au nanoparticles were partially embedded in the titanic acid nanofilm matrix. Based on an observation of the agglomerates in the low-magnification photograph in FIG. 1, combined with the electron beam penetration feature of the TEM, it can be found that the agglomerates are extremely thin, indicating that the agglomerates are not near-spherical ball with a stable structure, but rather flat aggregates of a large number of thin films, which were uniformly flattened on a TEM carbon mesh in the process of preparing TEM samples.

[0652] The two-dimensional titanic acid nanofilm material containing embedded Au nanoparticles was heated at 550? C. for 2 h to obtain the anatase TiO.sub.2 nanosheet powder containing embedded Au nanoparticles. The anatase TiO.sub.2 nanosheet has a thickness of 1.0-20 nm and an average area of greater than 500 nm.sup.2, and the particle size of the embedded Au nanoparticles is 1.0-10 nm. Its TEM morphology was shown in FIG. 2. Since the thickness of the TiO.sub.2 nanosheet was generally larger than the diameter of the Au nanoparticles, thus most of the Au nanoparticles were completely wrapped by the TiO.sub.2 nanosheet and existed in an embedded manner.

[0653] The two-dimensional titanic acid nanofilm material containing embedded Au nanoparticles was heated at 900? C. for 2 h to obtain a rutile TiO.sub.2 nanosheet powder containing embedded Au nanoparticles. The rutile TiO.sub.2 nanosheet had a thickness of 2.0-25 nm and an average area of more than 250 nm.sup.2. The particle size of the embedded Au nanoparticles was 1.5-12 nm.

[0654] When the two-dimensional sodium titanate nanofilm material containing embedded Au nanoparticles, the two-dimensional titanic acid nanofilm material containing embedded Au nanoparticles, and the anatase or rutile TiO.sub.2 nanosheet powder containing embedded Au nanoparticles were applied in polymer-based nanocomposites, catalytic materials, photocatalytic materials, and wastewater degradation materials, the presence of the embedded Au nanoparticles can obviously enhance the catalytic efficiency and wastewater degradation efficiency of the materials.

Embodiment 2

[0655] The embodiment provided a method of preparing a two-dimensional potassium titanate nanofilm material containing embedded Au nanoparticles, a two-dimensional titanic acid nanofilm material containing embedded Au nanoparticles and a TiO.sub.2 nanosheet powder containing embedded Au nanoparticles and an application thereof, including the following steps.

[0656] Weighing the metal Au, Ti and Al raw materials according to the ratio of Au.sub.1.5Ti.sub.33Al.sub.65.5 (atomic percentage), melting to obtain an alloy melt with the composition of Au.sub.1.5Ti.sub.33Al.sub.65.5; The alloy melt was solidified into an ingot, and then the ingot was broken into an Au.sub.1.5Ti.sub.33Al.sub.65.5 initial alloy powder with a particle size of no exceeding 50 ?m, which was mainly composed of a TiAl.sub.2 intermetallic compound solidly dissolved with Au.

[0657] Under atmospheric pressure, 0.5 g of the Au.sub.1.5Ti.sub.33Al.sub.65.5 initial alloy powder was added into 50 mL of KOH aqueous solution with a concentration of 12 mol/L and a temperature of 105? C.-115? C. with constant stirring. During a reaction with the concentrated alkali solution, the Au.sub.1.5Ti.sub.33Al.sub.65.5 initial alloy powder was subjected to nano-fragmentation through a violent hydrogen generation and Al-removal reaction, and reconfiguration of shape and composition to form a solid flocculent product, which was diffusely distributed in the alkaline solution.

[0658] The hydrogen generation and Al-removal reaction was finished within 20 s, and then the temperature was maintained for 2 h to confirm that after the hydrogen generation and Al-removal reaction was completed, the corresponding product could still be obtained after continuing to prolong the holding time of the temperature. The volume of the solution was maintained at a constant level of 50 mL by adding evaporated water during this process.

[0659] After 2 h, the hot alkaline solution containing the solid flocculated products was poured onto four stacked copper meshes with pore sizes of 200 ?m, 20 ?m, 5 ?m, and 5 ?m, respectively, at an angle of 45? to the horizontal plane, and the solid flocculated products were retained on the four stacked copper meshes, and the alkaline solution was filtered out while the temperature of the solid products was reduced to below 40? C. within 20 s.

[0660] The solid flocculent product was washed and dried, so as to obtain the two-dimensional potassium titanate nanofilm material containing embedded Au nanoparticles.

[0661] The thickness of the single film was about 0.25 nm?6 nm, and the average area of the film was larger than 1500 nm.sup.2. The particle size of the embedded Au nanoparticles was 1.0?10 nm.

[0662] The solid flocculent product as described above was dispersed in water, and then 0.025 mol/L HCl solution was gradually added to it, so that the pH value of the mixed solution was continuously decreased, and the pH value of the mixed solution was finally controlled between 2 and 5. After 10 min, the solid-liquid separation was carried out, and after being cleaned and dried i.e., the two-dimensional titanic acid nanofilm material containing embedded Au nanoparticles was obtained. The thickness of the single film was about 0.25 nm?6 nm, and the average area of the film was larger than 1500 nm.sup.2. The particle size of the embedded Au nanoparticles was 1.0?10 nm.

[0663] The two-dimensional titanic acid nanofilm material containing embedded Au nanoparticles was heated at 450? C. for 1 h to obtain a mixed product of a two-dimensional titanic acid nanofilm containing embedded Au nanoparticles and an anatase TiO.sub.2 nanosheets containing embedded Au nanoparticles. The thickness of the single film in the titanic acid nanofilm was about 0.25 nm?6 nm, and the average area of the film was larger than 1500 nm.sup.2. The thickness of the anatase TiO.sub.2 nanosheets was about 1.0?20 nm, and the average area of the nanosheet was larger than 500 nm.sup.2. The particle size of the embedded Au nanoparticles was 1.0?10 nm. The TEM morphology of the mixed product was shown in FIG. 3. It can be observed that the Au nanoparticles were combined with the titanic acid nanofilm matrix or TiO.sub.2 nanosheets in an obvious embedded manner. It was shown that the target product of the two-dimensional titanic acid nanofilm containing embedded Au nanoparticles and/or the TiO.sub.2 nanosheets containing embedded Au nanoparticles could still be obtained by maintaining the temperature for 2 hours after the hydrogen generation and Al-removal reaction was completed in combination with subsequent treating.

[0664] The two-dimensional titanic acid nanofilm material containing embedded Au nanoparticles was heated at 550? C. for 2 h to obtain the anatase TiO.sub.2 nanosheet powder containing embedded Au nanoparticles. The anatase TiO.sub.2 nanosheet had a thickness of 1.0?20 nm and an average area of larger than 500 nm.sup.2, The particle size of the embedded Au nanoparticles was 1.0?10 nm.

[0665] The above two-dimensional titanic acid nanofilm material containing embedded Au nanoparticles was heated at 700? C. for 2 h to obtain a mixed sheet powder of the anatase TiO.sub.2 nanosheet powder containing embedded Au nanoparticles and the rutile TiO.sub.2 nanosheet powder containing embedded Au nanoparticles. The nanosheet in the mixed sheet powder had a thickness of 1.0?25 nm and an average area of larger than 300 nm.sup.2. The particle size of the embedded Au nanoparticles was 1.0?12 nm.

[0666] The above two-dimensional titanic acid nanofilm material containing embedded Au nanoparticles was heated at 900? C. for 2 h to obtain the rutile TiO.sub.2 nanosheet powder containing embedded Au nanoparticles. The rutile TiO.sub.2 nanosheet had a thickness of 2.0?30 nm and an average area of larger than 200 nm.sup.2. The particle size of the embedded Au nanoparticles was 1.5?15 nm.

[0667] When the above two-dimensional potassium titanate nanofilm material containing embedded Au nanoparticles, the two-dimensional titanic acid nanofilm material containing embedded Au nanoparticles and the TiO.sub.2 nanosheet powder containing embedded Au nanoparticles are applied in photocatalysis, the presence of the embedded Au nanoparticles can obviously enhance the efficiency of photocatalytic conversion.

Embodiment 3

[0668] The embodiment provided a method of preparing a two-dimensional sodium titanate nanofilm material containing embedded Au(Cu) nanoparticles, a two-dimensional titanic acid nanofilm material containing embedded Au(Cu) nanoparticles, and a TiO.sub.2 nanosheet powder containing embedded Au(Cu) nanoparticles and an application thereof, including the following steps.

[0669] Weighing the metal Au, Cu, Ti and Al raw materials according to the ratio of Au.sub.3.5Cu.sub.0.5Ti.sub.24Al.sub.72 (atomic percentage), melting to obtain an alloy melt with the composition of Au.sub.3.5Cu.sub.0.5Ti.sub.24Al.sub.72; preparing the alloy melt into an initial alloy in the form of ribbons with a thickness of ?20 ?m by a rapid solidification method using melt spinning with copper roller. The initial alloy is mainly composed of TiAl.sub.3 intermetallic compounds containing solid dissolved Au and Cu.

[0670] Under atmospheric pressure, 0.5 g of the Au.sub.3.5Cu.sub.0.5Ti.sub.24Al.sub.72 initial alloy ribbon was added into 50 mL of NaOH aqueous solution with a concentration of 10 mol/L and a temperature of its boiling point (about 119? C.) while stirred continuously. During the reaction with the concentrated alkali solution, the Au.sub.3.5Cu.sub.0.5Ti.sub.24Al.sub.72 initial alloy ribbon was subjected to nano-fragmentation through a violent hydrogen generation and Al-removal reaction, and reconfiguration of shape and composition to form a solid flocculent product, which was diffusely distributed in the alkali solution.

[0671] The hydrogen generation and Al-removal reaction was finished within 15 s, and the temperature was maintained for 1 min to ensure that the reaction was completed. Then, 450 mL of room temperature water was rapidly poured into the reaction system at once under stirring. The concentration of the alkali in the solution was reduced to 1 mol/L within 2 s, and the temperature was reduced to below 45? C.

[0672] The solid flocculent product was separated from the alkali solution, and subjected to washing and drying, so as to obtain the two-dimensional sodium titanate nanofilm material containing embedded Au(Cu) nanoparticles. The thickness of the single film was about 0.25 nm 7 nm, and the average area of the film was larger than 500 nm.sup.2. The particle size of the embedded Au(Cu) nanoparticles was 1.0?20 nm. And a small amount of Cu was solidly dissolved in the Au(Cu) nanoparticles.

[0673] The solid flocculent product was dispersed in water, and then 0.025 mol/L HCl solution was gradually added to it, so that the pH value of the mixed solution was continuously decreased, and the pH value of the mixed solution was finally controlled between 2 and 5. After 5 min, the solid-liquid separation was carried out, and after being cleaned and dried i.e., the two-dimensional titanic acid nanofilm material containing embedded Au(Cu) nanoparticles was obtained. The thickness of the single film was about 0.25 nm?7 nm, and the average area of the film was larger than 500 nm.sup.2. The particle size of the embedded Au(Cu) nanoparticles was 1.0?10 nm. Its TEM morphology was shown in the low-magnification, mid-magnification and high-magnification photographs of FIG. 4. According to the observation of agglomerates in the low-magnification photograph in FIG. 4, combined with an electron beam penetration of the TEM, it can be found that the agglomerates was extremely thin, indicating that the agglomerates were not nearly spherical balls with a stable structure, and did not contain nanoporous or porous skeleton structures, but were rather flat aggregates of a large number of nanofilms, which were uniformly flattened on a TEM carbon mesh in the process of preparing TEM samples. Since the Au.sub.3.5Cu.sub.0.5Ti.sub.24Al.sub.72 initial alloy had a high content of Au and Cu, the content of the embedded Au(Cu) nanoparticles in the obtained two-dimensional titanic acid nanofilm material containing embedded Au(Cu) nanoparticles was also high, as shown in the low-magnification photograph in FIG. 4. Such a high and uniformly distributed content of the Au(Cu) nanoparticle can only be generated through in-situ embedding, because it was impossible to uniformly mix and generate the Au(Cu) nanoparticle through physical mixing at such a small scale. In addition, due to the high content of the embedded Au(Cu) nanoparticles, which had a certain impact on the shape of the nanofilm, the morphology of the nano titanate nanofilm shown in the mid-magnification photograph was not obvious, but the corresponding high-magnification photograph clearly shows a curled nanofilm structure. FIG. 5 showed the XRD spectrum of the obtained titanic acid nanofilm material containing embedded Au(Cu) nanoparticles, which clearly showed corresponding diffraction peaks of Au-based Au(Cu) nanoparticles. Since the titanic acid nanofilm was titanic acid with low crystallinity, its diffraction peak was not obvious.

[0674] The titanic acid nanofilm material containing embedded Au(Cu) nanoparticles was heated at 600? C. for 2 h to obtain an anatase TiO.sub.2 nanosheet powder containing embedded Au(Cu) nanoparticles. The anatase TiO.sub.2 nanosheet had a thickness of 1.0-20 nm and an average area of larger than 500 nm.sup.2. The particle size of the embedded Au(Cu) nanoparticles was 1.0-20 nm.

[0675] The titanic acid nanofilm material containing embedded Au(Cu) nanoparticles was heated at 900? C. for 2 h to obtain a rutile TiO.sub.2 nanosheet powder containing embedded Au(Cu) nanoparticles. The rutile TiO.sub.2 nanosheet had a thickness of 2.0?30 nm and an average area of larger than 250 nm.sup.2. The particle size of the embedded Au(Cu) nanoparticles was 1.5?30 nm.

[0676] The above solid flocculent material separated from the alkaline solution was reacted with 1 mol/L hydrochloric acid aqueous solution. 5 min later, the flocculent material matrix was dissolved in the acid through a reaction between the acid and the flocculent material matrix, while the Au(Cu) nanoparticles were freely detached, thereby obtaining freely dispersible Au(Cu) nanoparticles with a particle size of 2.0100 nm, as shown the TEM morphology in FIG. 6. Since the Au(Cu) nanoparticles can merge and grow up with each other after freely detaching, larger-sized Au(Cu) nanoparticles can also appear in the final Au(Cu) nanoparticles.

[0677] The above solid flocculent material separated from the alkaline solution was reacted with 1 mol/L hydrochloric acid aqueous solution. 72 h later, the flocculent material matrix was dissolved in the acid through a reaction between the acid and the flocculent material matrix, while the Cu in the Au(Cu) nanoparticles was also dissolved through the reaction with a higher concentration of acid and during a longer period of time, so as to obtain freely dispersible Au nanoparticles with a particle size of 2.0200 nm, as shown the TEM morphology in FIG. 7. Since the Au nanoparticles can merge and grow up with each other after freely detaching, larger-sized Au nanoparticles can also appear in the final Au nanoparticles.

[0678] When the two-dimensional sodium titanate nanofilm material containing embedded Au(Cu) nanoparticles, the two-dimensional titanic acid nanofilm material containing embedded Au(Cu) nanoparticles and the anatase TiO.sub.2 nanosheet powder containing embedded Au(Cu) nanoparticles were applied in photocatalysis, the presence of the embedded Au(Cu) nanoparticles can obviously enhance the photocatalytic conversion efficiency of composite materials.

Embodiment 4

[0679] The embodiment provided a method of preparing a two-dimensional sodium titanate nanothin film material containing embedded CuO nanoparticles, a two-dimensional titanic acid nanofilm material containing embedded CuO nanoparticles, and a TiO.sub.2 nanosheet powder containing embedded CuO nanoparticles and an application thereof, including the following steps:

[0680] Weighing the metal Cu, Ti and Al raw materials according to the ratio of Cu.sub.2Ti.sub.24.5Al.sub.73.5 (atomic percentage), melting to obtain an alloy melt with the composition of Cu.sub.2Ti.sub.24.5Al.sub.73.5; preparing the alloy melt into an initial alloy ribbons with a thickness of ?20 ?m by a rapid solidification method using melt spinning with copper roller. The initial alloy is mainly composed of TiAl.sub.3 intermetallic compounds containing solid dissolved Cu.

[0681] Under atmospheric pressure, 0.5 g of the Cu.sub.2Ti.sub.24.5Al.sub.73.5 initial alloy ribbon was added into 50 mL of NaOH aqueous solution with a concentration of 10 mol/L and a temperature of its boiling point (about 119? C.) while stirred continuously. During the reaction with the concentrated alkaline solution, the Cu.sub.2Ti.sub.24.5Al.sub.73.5 initial alloy ribbon was subjected to nano-fragmentation through a violent hydrogen generation and Al-removal reaction, and reconfiguration of shape and composition to form a solid flocculent product, which was diffusely distributed in the alkaline solution.

[0682] The hydrogen generation and Al-removal reaction was finished within 15 s, and the temperature was maintained for 1 min to ensure that the reaction was completed. Then, 450 mL of room temperature water was rapidly poured into the reaction system at once under stirring. The concentration of the alkali in the solution was reduced to 1 mol/L within 2 s, and the temperature was reduced to below 45? C.

[0683] The solid flocculent product was separated from the alkaline solution, and subjected to washing and drying, so as to obtain the two-dimensional sodium titanate nanofilm material containing embedded CuO nanoparticles. The thickness of the single film was about 0.25 nm?6 nm, and the average area of the film was larger than 1000 nm.sup.2. The particle size of the embedded CuO nanoparticles was 1.0?12 nm.

[0684] The above solid flocculent product was dispersed in water, and gradually added with 0.025 mol/L HCl solution to continuously reduce pH of the mixed solution, and the pH of the mixed solution was ultimately controlled between 3 and 5. 5 min later, the mixed solution was subjected to solid-liquid separation, washing and drying, so as to obtain the two-dimensional titanic acid nanofilm material containing embedded CuO nanoparticles. The thickness of the single film was about 0.25 nm?6 nm, and the average area of the film was larger than 1000 nm.sup.2. The particle size of the embedded CuO nanoparticles was 1.0?12 nm. Its TEM morphology was shown in FIG. 8. The CuO nanoparticles were distributed in the titanic acid nanofilm be means of embedding, which protected the embedded CuO nanoparticles from being removed by the reaction with the dilute acid solution. The XRD spectrum of the CuO nanoparticles was shown in FIG. 9. The CuO nanoparticles had obvious CuO diffraction peaks, and the titanic acid nanofilm matrix was low-crystallinity titanic acid.

[0685] The titanic acid nanofilm material containing embedded CuO nanoparticles was heated at 600? C. for 2 h to obtain an anatase TiO.sub.2 nanosheet powder containing embedded CuO nanoparticles. The anatase TiO.sub.2 nanosheet had a thickness of 1.0-20 nm and an average area of larger than 500 nm.sup.2. The particle size of the embedded CuO nanoparticles was 1.0?15 nm.

[0686] The above titanic acid nanofilm material containing embedded CuO nanoparticles was heated at 900? C. for 2 h to obtain a rutile TiO.sub.2 nanosheet powder containing embedded CuO nanoparticles. The rutile TiO.sub.2 nanosheet had a thickness of 2.0?30 nm and an average area of larger than 200 nm.sup.2. The particle size of the embedded CuO nanoparticles was 1.5?20 nm.

[0687] The above sodium titanate nanofilm material containing embedded CuO nanoparticles, titanic acid nanofilm material containing embedded CuO nanoparticles and anatase TiO.sub.2 nanosheet powder containing embedded CuO nanoparticles were used in photocatalysis, and the presence of the embedded CuO nanoparticles can obviously enhance the efficiency of photocatalytic conversion of the composite materials.

[0688] Application as a home furnishing coating: The above titanic acid nanofilm material containing embedded CuO nanoparticles was mixed with other components as a coating additive and coated together on surfaces of furniture, utensils, and walls to achieve an antimicrobial effect.

[0689] Application as a sterilizing spray: The above titanic acid nanofilm material containing embedded CuO nanoparticles was mixed with other liquid spray components, then the mixture were sprayed on the surfaces of furniture, utensils, fabrics, and walls through a spray carrier, thus an antibacterial effect of the composite materials can be achieved.

[0690] Application as an antifouling coating: The above titanic acid nanofilm material containing embedded CuO nanoparticles was used to replace the bactericidal antifouling component in conventional antifouling coatings to achieve an antifouling effect.

[0691] Application in antimicrobial fabrics: The above titanic acid nanofilm material containing embedded CuO nanoparticles was scattered such that it can be attached to or coated on the surfaces of a fabric or mixed and knitted with the fabric, thereby allowing the fabric to have an antimicrobial and bactericidal effect and capability.

Embodiment 5

[0692] The embodiment provided a method of preparing a sodium titanate nanofilm material containing embedded AuPdPtCuAg nanoparticles, a titanic acid nanofilm material containing embedded AuPdPtCuAg nanoparticles, and a TiO.sub.2 nanosheet powder containing embedded AuPdPtCuAg nanoparticles, including the following steps:

[0693] The Au, Pd, Pt, Cu, Ag, Ti and Zn metal raw materials weighed according to a ratio (atomic percentage) of Au.sub.1.5Pd.sub.0.25Pt.sub.0.25Cu.sub.0.25Ag.sub.0.25Ti.sub.24Zn.sub.73.5 were melted to obtain an alloy melt with a composition of Au.sub.1.5Pd.sub.0.25Pt.sub.0.25Cu.sub.0.25Ag.sub.0.25Ti.sub.24Zn.sub.73.5 Through a rapid solidification method using melt spinning with copper roller, the alloy melt was prepared into a Cu.sub.2Ti.sub.24.5Al.sub.73.5 initial alloy ribbon with a thickness of 200 ?m. The initial alloy ribbon was mainly composed of a TiZn.sub.3 intermetallic compound solidly dissolved with Au, Pd, Pt, Cu and Ag.

[0694] Under atmospheric pressure, 0.5 g of the Au.sub.1.5Pd.sub.0.25Pt.sub.0.25Cu.sub.0.25Ag.sub.0.25Ti.sub.24Zn.sub.73.5 initial alloy ribbon was added into 50 mL of NaOH aqueous solution with a concentration of 15 mol/L and a temperature of its boiling point (about 140? C.) while stirred continuously. During the reaction with the concentrated alkali solution, the Au.sub.1.5Pd.sub.0.25Pt.sub.0.25Cu.sub.0.25Ag.sub.0.25Ti.sub.24Zn.sub.73.5 initial alloy ribbon was subjected to nano-fragmentation through a violent hydrogen generation and Zn-removal reaction, and reconfiguration of shape and composition to form a solid flocculent product, which was diffusely distributed in the alkali solution.

[0695] The hydrogen generation and Zn-removal reaction was finished within 1 min, and the temperature was maintained for 1 min to ensure that the reaction was completed. Then, 700 mL of room temperature water was rapidly poured into the reaction system at once under stirring. The concentration of the alkali in the solution was reduced to 1 mol/L within 2 s, and the temperature was reduced to below 45? C.

[0696] The above solid flocculent product was separated from the alkaline solution, and subjected to washing and drying, so as to obtain the sodium titanate nanofilm material containing embedded AuPdPtCuAg nanoparticles. The thickness of the single film was about 0.25 nm?6 nm, and the average area of the film was larger than 1000 nm.sup.2. The particle size of the embedded AuPdPtCuAg nanoparticles was 1.0?15 nm.

[0697] The above solid flocculent product was dispersed in water, and gradually added with 0.025 mol/L HCl solution to continuously reduce pH of the mixed solution, and the pH of the mixed solution was ultimately controlled between 2 and 5. 5 min later, the mixed solution was subjected to solid-liquid separation, washing and drying, so as to obtain the titanic acid nanofilm material containing embedded AuPdPtCuAg nanoparticles. The thickness of the single film was about 0.25 nm?6 nm, and the average area of the film was larger than 1000 nm.sup.2. The particle size of the embedded AuPdPtCuAg nanoparticles was 1.0?15 nm. Its TEM morphology was shown in FIG. 10.

[0698] The titanic acid nanofilm material containing embedded AuPdPtCuAg nanoparticles was heated at 550? C. for 3 h to obtain an anatase TiO.sub.2 nanosheet powder containing embedded AuPdPtCuAg nanoparticles. The anatase TiO.sub.2 nanosheet had a thickness of 1.0?20 nm and an average area of larger than 500 nm.sup.2. The particle size of the embedded AuPdPtCuAg nanoparticles was 1.0?15 nm.

[0699] The above titanic acid nanofilm material containing embedded AuPdPtCuAg nanoparticles was heated at 900? C. for 2 h to obtain a rutile TiO.sub.2 nanosheet powder containing embedded AuPdPtCuAg nanoparticles. The rutile TiO.sub.2 nanosheet had a thickness of 2.0?30 nm and an average area of larger than 200 nm.sup.2. The particle size of the embedded CuO nanoparticles was 1.5?25 nm.

Embodiment 6

[0700] The embodiment provided a method of preparing a sodium titanate nanotube containing embedded Au nanoparticles, a titanic acid nanotube containing embedded Au nanoparticles, and a TiO.sub.2 nanotube/rod containing embedded Au nanoparticles, including the following steps:

[0701] The Au, Ti and Al metal raw materials weighed according to a ratio (atomic percentage) of Au.sub.1Ti.sub.24.75Al.sub.74.25 were melted to obtain an alloy melt with a composition of Au.sub.1Ti.sub.24.75Al.sub.74.25. The alloy melt was solidified into an ingot, and then broken into an Au.sub.1Ti.sub.24.75Al.sub.74.25 initial alloy powder with a particle size of 1 mm or less. The initial alloy was mainly composed of a TiAl.sub.3 intermetallic compound solidly dissolved with Au.

[0702] Under atmospheric pressure, 0.5 g of the Au.sub.1Ti.sub.24.75Al.sub.74.25 initial alloy powder was added into 50 mL of NaOH aqueous solution with a concentration of 10 mol/L and a temperature of its boiling point (about 119? C.) while stirred continuously. During the reaction with the concentrated alkaline solution, the Au.sub.1Ti.sub.24.75Al.sub.74.25 initial alloy was subjected to nano-fragmentation through a violent hydrogen generation and Al-removal reaction, and reconfiguration of shape and composition to form a solid flocculent product, which was diffusely distributed in the alkaline solution.

[0703] The hydrogen generation and Al-removal reaction was finished within 5 min. The alkaline solution containing the solid flocculent product was sealed in a reaction vessel lined with polytetrafluoroethylene. The temperature of the sealed reaction vessel and the initial alloy and NaOH aqueous solution therein was immediately raised to 250? C. within 10 min, and then maintained for 20 min.

[0704] 20 min later, the reaction vessel was placed in cold water for rapid cooling. After the reaction vessel was cooled to room temperature, the pressure in the reaction vessel was restored to atmospheric pressure. Then, a solid matter in the reaction vessel was subjected to separation from the alkaline solution, washing and drying, so as to obtain the sodium titanate nanotube containing embedded Au nanoparticles with an outer diameter of 3?12 nm and a length of more than 5 times the outer diameter. The particle size of the embedded Au nanoparticles was 1.5?12 nm.

[0705] The solid product separated from the alkaline solution was dispersed in water, and gradually added with 0.025 mol/L HCl solution to continuously reduce pH of the mixed solution, and the pH of the mixed solution was ultimately controlled between 2 and 5. 5 min later, the mixed solution was subjected to solid-liquid separation, washing and drying, so as to obtain the titanic acid nanotube containing embedded Au nanoparticles with an outer diameter of 3?12 nm and a length of more than 5 times the outer diameter. The particle size of the embedded Au nanoparticles was 1.5?12 nm.

[0706] The above titanic acid nanotube containing embedded Au nanoparticles was heated at 600? C. for 2 h to obtain an anatase TiO.sub.2 nanotube containing embedded Au nanoparticles with an outer diameter of 3?15 nm and a length of more than 5 times the outer diameter. The particle size of the embedded Au nanoparticles was 1.5?15 nm.

[0707] The above titanic acid nanotube containing embedded Au nanoparticles was heated at 950? C. for 2 h to obtain a rutile TiO.sub.2 nanotube/rod containing embedded Au nanoparticles with an outer diameter of 3-25 nm and a length of more than 3 times the outer diameter. The particle size of the embedded Au nanoparticles was 1.5?25 nm.

Embodiment 7

[0708] The embodiment provided a method of preparing a potassium titanate nanotube containing embedded Au nanoparticles, a titanic acid nanotube containing embedded Au nanoparticles, and a TiO.sub.2 nanotube containing embedded Au nanoparticles, including the following steps.

[0709] The Au, Ti and Zn metal raw materials weighed according to a ratio (atomic percentage) of Au.sub.1Ti.sub.24.75Zn.sub.74.25 were melted to obtain an alloy melt with a composition of Au.sub.1Ti.sub.24.75Zn.sub.74.25. The alloy melt was solidified into an ingot, which was mainly composed of a TiZn.sub.3 intermetallic compound solidly dissolved Au. The ingot was broken into an Au.sub.1Ti.sub.24.75Zn.sub.74.25 initial alloy powder with a particle size of 50 ?m or less.

[0710] Under atmospheric pressure, 0.5 g of the Au.sub.1Ti.sub.24.75Zn.sub.74.25 initial alloy powder was added into 50 mL of KOH aqueous solution with a concentration of 10 mol/L and a temperature of its boiling point (about 125? C.) while stirred continuously. During The reaction with the concentrated alkaline solution, the Au.sub.1Ti.sub.24.75Zn.sub.74.25 initial alloy was subjected to nano-fragmentation through a violent hydrogen generation and Zn-removal reaction, and a reconfiguration of shape and composition to form a solid flocculent product, which was diffusely distributed in the alkaline solution.

[0711] The hydrogen generation and Zn-removal reaction was finished within 20 s. The alkaline solution containing the solid flocculent product was sealed in a reaction vessel lined with polytetrafluoroethylene. The temperature of the sealed reaction vessel and the initial alloy and NaOH aqueous solution therein was immediately raised to 250? C. within 10 min, and then maintained for 20 min.

[0712] 20 min later, the reaction vessel was placed in cold water for rapid cooling. After the reaction vessel was cooled to room temperature, the pressure in the reaction vessel was restored to atmospheric pressure. Then, a solid product in the reaction vessel was subjected to separation from the alkaline solution, washing and drying, so as to obtain the potassium titanate nanotube containing embedded Au nanoparticles with an outer diameter of 3-15 nm and a length of more than 5 times the outer diameter. The particle size of the embedded Au nanoparticles was 0.5-12 nm.

[0713] The solid product separated from the alkaline solution was dispersed in water, and gradually added with 0.025 mol/L HCl solution to continuously reduce pH of the mixed solution, and the pH of the mixed solution was ultimately controlled between 2 and 5. 5 min later, the mixed solution was subjected to solid-liquid separation, washing and drying, so as to obtain the titanic acid nanotube containing embedded Au nanoparticles with an outer diameter of 3-15 nm and a length of more than 5 times the outer diameter. The particle size of the embedded Au nanoparticles was 1.5?12 nm.

[0714] The above titanic acid nanotube containing embedded Au nanoparticles was heated at 600? C. for 2 h to obtain an anatase TiO.sub.2 nanotube with an outer diameter of 3-15 nm and a length of more than 5 times the outer diameter. The particle size of the embedded Au nanoparticles was 1.5?15 nm.

[0715] The above titanic acid nanotube containing embedded Au nanoparticles was heated at 950? C. for 2 h to obtain a rutile TiO.sub.2 nanotube/rod with an outer diameter of 3-25 nm and a length of more than 3 times the outer diameter. The particle size of the embedded Au nanoparticles was 1.5?25 nm.

Embodiment 8

[0716] The embodiment provided a method of preparing a sodium titanate nanotube containing embedded Au nanoparticles, a titanic acid nanotube containing embedded Au nanoparticles, and a TiO.sub.2 nanotube/rod containing embedded Au nanoparticles, including the following steps:

[0717] The Au, Ti and Al metal raw materials weighed according to a ratio (atomic percentage) of Au.sub.1Ti.sub.24.75Zn.sub.74.25 were melted to obtain an alloy melt with a composition of Au.sub.1Ti.sub.24.75Zn.sub.74.25. Through a rapid solidification method using melt spinning with copper roller, the alloy melt was prepared into an Au.sub.1Ti.sub.24.75Zn.sub.74.25 initial alloy ribbon with a thickness of 25 ?m. The initial alloy is mainly composed of TiAl.sub.3 intermetallic compounds containing solid dissolved Au.

[0718] At atmospheric temperature and pressure, 0.5 g of the Au.sub.1Ti.sub.24.75Zn.sub.74.25 initial alloy ribbon and 50 mL of NaOH aqueous solution with a concentration of 10 mol/L were placed in a sealed reaction vessel lined with polytetrafluoroethylene. The temperature of the sealed reaction vessel and the initial alloy and NaOH aqueous solution therein was immediately raised to 250? C. within 10 min, and then maintained for 25 min.

[0719] 25 min later, the reaction vessel was placed in cold water for rapid cooling. After the reaction vessel was cooled to room temperature, the pressure in the reaction vessel was restored to atmospheric pressure. Then, a solid product in the reaction vessel was subjected to separation from the alkaline solution, washing and drying, so as to obtain the sodium titanate nanotube containing embedded Au nanoparticles, with an outer diameter of 3-15 nm and a length of more than 5 times the outer diameter. The particle size of the embedded Au nanoparticles was 0.5-12 nm.

[0720] The solid product separated from the alkaline solution was dispersed in water, and gradually added with 0.025 mol/L HCl solution to continuously reduce pH of the mixed solution, and the pH of the mixed solution was ultimately controlled between 2 and 5. 5 min later, the mixed solution was subjected to solid-liquid separation, washing and drying, so as to obtain the titanic acid nanotube containing embedded Au nanoparticles with an outer diameter of 3-15 nm and a length of more than 5 times the outer diameter. The particle size of the embedded Au nanoparticles was 1.5?12 nm.

[0721] The above titanic acid nanotube containing embedded Au nanoparticles was heated at 600? C. for 2 h to obtain an anatase TiO.sub.2 nanotube with an outer diameter of 3-15 nm and a length of more than 5 times the outer diameter. The particle size of the embedded Au nanoparticles was 1.5?15 nm.

[0722] The above titanic acid nanotube containing embedded Au nanoparticles was heated at 950? C. for 2 h to obtain a rutile TiO.sub.2 nanotube/rod with an outer diameter of 3-25 nm and a length of more than 3 times the outer diameter. The particle size of the embedded Au nanoparticles was 1.5?25 nm.

Embodiment 9

[0723] The embodiment provided a method of preparing a potassium titanate nanotube containing embedded Au-Tr nanoparticles, a titanic acid nanotube containing embedded Au-Tr nanoparticles, and a TiO.sub.2 nanotube/rod containing embedded Au-Tr nanoparticles, including the following steps:

[0724] The Au, Ir, Ti and Zn metal raw materials weighed according to a ratio (atomic percentage) of Au.sub.2Ir.sub.0.5Ti.sub.32Zn.sub.65.5 were melted to obtain an alloy melt with a composition of Au.sub.2Ir.sub.0.5Ti.sub.32Zn.sub.65.5. Through a rapid solidification method using melt spinning with copper roller, the alloy melt was prepared into an Au.sub.2Ir.sub.0.5Ti.sub.32Zn.sub.65.5 initial alloy ribbon with a thickness of 25 ?m which was mainly composed of a TiZn.sub.2 intermetallic compound solidly dissolved with Au and Ir.

[0725] At atmospheric temperature and pressure, 0.5 g of the Au.sub.2Ir.sub.0.5Ti.sub.32Zn.sub.65.5 initial alloy ribbon and 50 mL of KOH aqueous solution with a concentration of 10 mol/L were placed in a sealed reaction vessel lined with polytetrafluoroethylene. The temperature of the sealed reaction vessel and the initial alloy and NaOH aqueous solution therein was immediately raised to 250? C. within 10 min, and then maintained for 10 min.

[0726] 10 min later, the reaction vessel was placed in cold water for rapid cooling. After the reaction vessel was cooled to room temperature, the pressure in the reaction vessel was restored to atmospheric pressure. Then, a solid product in the reaction vessel was subjected to separation from the alkaline solution, washing and drying, so as to obtain the potassium titanate nanotube containing embedded AuIr nanoparticles with an outer diameter of 3-15 nm and a length of more than 5 times the outer diameter. The particle size of the embedded AuIr nanoparticles was 0.5-12 nm.

[0727] The solid product separated from the alkaline solution was dispersed in water, and gradually added with 0.025 mol/L HCl solution to continuously reduce pH of the mixed solution, and the pH of the mixed solution was ultimately controlled between 2 and 5. 5 min later, the mixed solution was subjected to solid-liquid separation, washing and drying, so as to obtain the titanic acid nanotube containing embedded AuIr nanoparticles with an outer diameter of 3-15 nm and a length of more than 5 times the outer diameter. The particle size of the embedded AuIr nanoparticles was 1.5?12 nm.

[0728] The above titanic acid nanotube containing embedded AuIr nanoparticles was heated at 600? C. for 2 h to obtain an anatase TiO.sub.2 nanotube containing embedded AuIr nanoparticles with an outer diameter of 3-15 nm and a length of more than 5 times the outer diameter. The particle size of the embedded AuIr nanoparticles was 1.5?15 nm.

[0729] The above titanic acid nanotube containing embedded AuIr nanoparticles was heated at 950? C. for 2 h to obtain a rutile TiO.sub.2 nanotube/rod containing embedded AuIr nanoparticles with an outer diameter of 3-25 nm and a length of more than 3 times the outer diameter. The particle size of the embedded Au nanoparticles was 1.5?25 nm.

Embodiment 10

[0730] The embodiment provided a method of preparing a potassium titanate nanofilm material containing embedded Au nanoparticles, including the following steps:

[0731] The Au, Ti and Al metal raw materials weighed according to a ratio (atomic percentage) of Au.sub.1Ti.sub.24.75Al.sub.74.25 were melted to obtain an alloy melt with a composition of Au.sub.1Ti.sub.24.75Al.sub.74.25. Through a rapid solidification method using melt spinning with copper roller, the alloy melt was prepared into an Au.sub.1Ti.sub.24.75Al.sub.74.25 initial alloy ribbon with a thickness of ?20 ?m. The initial alloy was mainly composed of a TiAl.sub.3 intermetallic compound solidly dissolved with Au.

[0732] Under atmospheric pressure, 0.25 g of the Au.sub.1Ti.sub.24.75Al.sub.74.25 initial alloy ribbon and 50 mL of KOH aqueous solution with a concentration of 15 mol/L and a temperature of 60? C. with constant stirring. During a reaction with the concentrated alkali solution, the Au.sub.1Ti.sub.24.75Al.sub.74.25 initial alloy ribbon was subjected to nano-fragmentation through a violent hydrogen generation and Al-removal reaction, and reconfiguration of shape and composition to form a solid flocculent product, which was diffusely distributed in the alkaline solution.

[0733] The hydrogen generation and Al-removal reaction was finished within 4 min, and then an insulation was maintained for 2 min to confirm that the hydrogen generation and Al-removal reaction was completed. Then, the hot concentrated alkaline solution containing the solid flocculent product was poured onto a five-layer copper mesh with pore sizes of 200 ?m, 20 ?m, 5 ?m, 5 ?m and 5 ?m, respectively, at an angle of 45? the horizontal plane. The solid flocculent product was retained on the five-layer copper mesh. The alkaline solution was filtered out, while the temperature of the solid flocculent product was reduced to below 40? C. within 10 s.

[0734] The obtained solid flocculent product was washed and dried, so as to obtain the potassium titanate nanofilm material containing embedded Au nanoparticles with a yield of more than 60%. The thickness of the single film was about 0.25 nm?5 nm, and the average area of the film was larger than 1000 nm.sup.2. The particle size of the embedded Au nanoparticles was 1.0-12 nm.

Embodiment 11

[0735] The embodiment provided a method of preparing a sodium titanate nanofilm powder material containing embedded Au nanoparticles, a titanic acid nanofilm powder material containing embedded Au nanoparticles, including the following steps:

[0736] The Au, Ti and Al metal raw materials weighed according to a ratio (atomic percentage) of Au.sub.1.5Ti.sub.24.5Al.sub.74 were melted to obtain an alloy melt with a composition of Au.sub.1.5Ti.sub.24.5Al.sub.74. Through a rapid solidification method using melt spinning with copper roller, the alloy melt was prepared into an Au.sub.1.5Ti.sub.24.5Al.sub.74 initial alloy ribbon with a thickness of ?25 ?m. The initial alloy was mainly composed of a TiAl.sub.3 intermetallic compound solidly dissolved with Au.

[0737] Under atmospheric pressure, 0.5 g of the Au.sub.1.5Ti.sub.24.5Al.sub.74 initial alloy ribbon and 50 mL of NaOH aqueous solution with a concentration of 10 mol/L were placed in a closed vessel. At the beginning, the initial alloy ribbon was not in contact with the alkaline solution.

[0738] The temperature inside the closed vessel, as well as the temperature of the initial alloy ribbon and the alkaline solution was raised to 180? C., at which time the closed vessel was in a high-pressure state. Then, the Au.sub.1.5Ti.sub.24.5Al.sub.74 initial alloy ribbon and the alkaline solution at this temperature in the closed vessel were mixed together to subject to a violent hydrogen generation and Al-removal reaction. The Au.sub.1.5Ti.sub.24.5Al.sub.74 alloy ribbon was subjected to nano-fragmentation through a violent hydrogen generation and Al-removal reaction, and reconfiguration of shape and composition to form a solid flocculent product containing Au.

[0739] The hydrogen generation and Al-removal reaction was finished within 10 s. 10 s later, the closed vessel and the reaction system were put into cooling water, and the inner pressure of the closed vessel was simultaneously lowered to atmospheric pressure.

[0740] After the temperature of the reaction system was reduced to atmospheric temperature and pressure, the solid flocculent product was subjected to separation from the alkaline solution, washing and drying, so as to obtain the sodium titanate nanofilm powder material containing embedded Au nanoparticles, with a thickness of a single film of 0.25-5 nm and an average area of greater than 2000 nm.sup.2. The particle size of the embedded Au nanoparticles was 1.0?10 nm.

[0741] The above solid flocculent product separated from the alkaline solution was dispersed in water, and gradually added with 0.025 mol/L HCl solution, such that the pH of the mixed solution was continuously reduced and finally controlled between 2 and 5. 5 min later, the mixed solution was subjected to solid-liquid separation, washing and drying, so as to obtain the titanic acid nanofilm powder material containing embedded Au nanoparticles with a thickness of a single film of 0.25-5 nm and an average area of greater than 2000 nm.sup.2. The particle size of the embedded Au nanoparticles was 1.0?10 nm.

Comparative Example 1

[0742] In an atmospheric environment, 1 g of anatase TiO.sub.2 powder with a particle size of 50-100 nm was added into 50 mL of NaOH aqueous solution with a concentration of 10 mol/L and a temperature of its boiling point (119? C.) with constant stirring.

[0743] 10 min later, while stirring, 450 mL of normal temperature water was rapidly poured into the reaction system. In the solution, the concentration of the alkaline solution was reduced to 1 mol/L, and the temperature was reduced to below 40? C.

[0744] The above solid product was subjected to separation from the solution, washing and drying, so as to obtain a desired product. The XRD spectrum of the product was obtained, as shown in FIG. 11.

[0745] Combined with FIG. 12, which shows an XRD spectrum of the anatase TiO.sub.2 powder before reacting, it can be concluded that after reacting for 10 min with the alkaline solution, there was almost no change in the anatase TiO.sub.2. According to a width of an XRD peak, it can be judged that there was also no significant change in the particle size of the TiO.sub.2 particles. The comparative example herein showed that when the Titanium source was TiO.sub.2 powder, it was difficult to break a TiO bond of TiO.sub.2 in a short time at the boiling point of the alkaline solution in the atmospheric environment.

Comparative Example 2

[0746] The Au, Ti and Al metal raw materials weighed according to a ratio (atomic percentage) of Au.sub.1Ti.sub.24.75Al.sub.74.25 were melted to obtain an alloy melt with a composition of Au.sub.1Ti.sub.24.75Al.sub.74.25. The alloy melt was solidified into an alloy ingot, and then crushed into an initial alloy powder with a particle size of no more than 30 ?m. The phase composition of the initial alloy mainly composed of TiAl.sub.3 intermetallic compound solidly dissolved with Au.

[0747] Under atmospheric pressure, the above initial alloy powder was reacted with a 10 mol/L NaOH solution with a temperature of 35? C. for 2 h to obtain a product as shown in FIGS. 13 and 14. It can be seen that under this reaction condition, The shape of the initial alloy powder before and after the reaction was roughly unchanged, which was still original broken and angular powder particles, as an angular morphology shown in FIGS. 13 and 14. Moreover, in terms of microstructure, instead of generating a large number of monolithic two-dimensional film-like products, angular powder particles composed of nanoporous network structures were generated. Therefore, a reaction equilibrium between the initial alloy and the alkaline solution which occurred at a lower temperature was completely different from a reaction equilibrium which occurred near the boiling point of the alkaline solution in the present disclosure, as well as a morphology of the product.

[0748] The technical features of the above examples may be arbitrarily combined. For conciseness, all possible combinations of the technical features of the above embodiments have not been completely described. However, as long as there is no contradiction between the combinations of these technical features, they shall be considered to be within the scope of the present disclosure.

[0749] The above examples only express several embodiments of the disclosure, and their descriptions are more specific and detailed, but they cannot be interpreted as a limitation on the scope of the present disclosure. It should be noted that for one of ordinary skill in the art, several variations and improvements may be made without deviating from the concept of the disclosure, which all fall within the scope of protection of the disclosure. Therefore, the scope of protection of the present disclosure shall be subject to the attached claims.