Titanium ligand-modified black phosphorus and preparation method and use thereof

Abstract

The present invention provides a titanium ligand-modified black phosphorus and the preparation method and use thereof. The titanium ligand-modified black phosphorus is a complex of black phosphorus and a titanium ligand having a structure represented by formula (I): ##STR00001##
wherein in the formula (I), R.sub.1 comprises C.sub.1-C.sub.6 alkyl, or phenyl optionally further substituted with 0 to 5 groups each independently selected from halogen atom, C.sub.1-C.sub.6 alkyl, nitro, hydroxy, amino or C.sub.1-C.sub.3 alkoxy; the C.sub.1-C.sub.6 alkyl or C.sub.1-C.sub.3 alkoxy is optionally further substituted with 0 to 3 groups each independently selected from halogen atom, nitro, hydroxy, amino, methyl, ethyl or n-propyl. The titanium ligand-modified black phosphorus of the present invention is not likely oxidized without changing inherent properties of the black phosphorus, and the antioxidant capacity is greatly enhanced.

Claims

1. A titanium ligand-modified black phosphorus, which is a complex of black phosphorus and a titanium ligand having a structure represented by formula (I): ##STR00011## wherein in the formula (I), R.sub.1 comprises C.sub.1-C.sub.6 alkyl, or phenyl optionally further substituted with 0 to 5 groups each independently selected from halogen atom, C.sub.1-C.sub.6 alkyl, nitro, hydroxy, amino or C.sub.1-C.sub.3 alkoxy; the C.sub.1-C.sub.6 alkyl or C.sub.1-C.sub.3 alkoxy is optionally further substituted with 0 to 3 groups each independently selected from halogen atom, nitro, hydroxy, amino, methyl, ethyl or n-propyl.

2. The titanium ligand-modified black phosphorus according to claim 1, wherein the halogen atom is fluorine atom.

3. The titanium ligand-modified black phosphorus according to claim 1, wherein the titanium ligand comprises: ##STR00012## ##STR00013## ##STR00014##

4. The titanium ligand-modified black phosphorus according to claim 1, wherein the black phosphorus comprises one or more of black phosphorous bulk material, multilayered black phosphorous nanosheet, monolayer black phosphorous nanosheet and black phosphorus quantum dot, and wherein the multilayered black phosphorous nanosheet refers to a black phosphorus nanosheet having two or more atomic layers and at a thickness of less than 100 nm.

5. A method of producing the titanium ligand-modified black phosphorus according to claim 1, comprising the steps of: providing the titanium ligand and the black phosphorus in an organic solvent to take place a reaction protected from light under an inert condition to obtain the titanium ligand-modified black phosphorus.

6. The method according claim 5, wherein the titanium ligand comprises: ##STR00015## ##STR00016## ##STR00017##

7. The method according to claim 6, wherein the organic solvent comprises polar solvent and/or non-polar solvent, and the polar solvent comprises polar protic solvent and/or polar aprotic solvent.

8. The method according to claim 6, wherein the reaction is carried out at 4 to 45 C. for 12 to 24 h.

9. A composition comprising the titanium ligand-modified black phosphorus according to claim 1.

10. The composition according to claim 9, wherein the halogen atom is fluorine atom.

11. The composition according to claim 9, wherein the titanium ligand comprises: ##STR00018## ##STR00019## ##STR00020##

12. A composition according to claim 9, wherein the black phosphorus comprises one or more of black phosphorous bulk material, multilayered black phosphorous nanosheet, monolayer black phosphorous nanosheet and black phosphorus quantum dot, and wherein the multilayered black phosphorous nanosheet refers to a black phosphorus nanosheet having two or more atomic layers and at a thickness of less than 100 nm.

13. A method for preparing materials selected from the group consisting of a thin film transistor material, a negative electrode material for battery, a flexible display material, a LED material, an optical switch material, a biosensor material, a photodynamic therapeutic agent for killing cancer cells and a photothermal therapeutic agent for killing cancer cells, comprising providing the titanium ligand-modified black phosphorus according to claim 1.

14. The method according to claim 13, wherein the halogen atom is fluorine atom.

15. The method according to claim 13, wherein the titanium ligand comprises: ##STR00021## ##STR00022## ##STR00023##

16. The method according to claim 13, wherein the black phosphorus comprises one or more of black phosphorous bulk material, multilayered black phosphorous nanosheet, monolayer black phosphorous nanosheet and black phosphorus quantum dot, and wherein the multilayered black phosphorous nanosheet refers to a black phosphorus nanosheet having two or more atomic layers and at a thickness of less than 100 nm.

17. A method for preparing materials selected from the group consisting of a thin film transistor material, a negative electrode material for battery, a flexible display material, a LED material, an optical switch material, a biosensor material, a photodynamic therapeutic agent for killing cancer cells and a photothermal therapeutic agent for killing cancer cells, comprising providing the titanium ligand-modified black phosphorus composition of claim 9.

18. The method according to claim 17, wherein the halogen atom is fluorine atom.

19. The method according to claim 17, wherein the titanium ligand comprises: ##STR00024## ##STR00025## ##STR00026##

20. The method according to claim 17, wherein the black phosphorus comprises one or more of black phosphorous bulk material, multilayered black phosphorous nanosheet, monolayer black phosphorous nanosheet and black phosphorus quantum dot, and wherein the multilayered black phosphorous nanosheet refers to a black phosphorus nanosheet having two or more atomic layers and at a thickness of less than 100 nm.

21. The titanium ligand-modified black phosphorus according to claim 1, wherein the C.sub.1-C.sub.6 alkyl is C.sub.1-C.sub.3 alkyl.

22. The method according to claim 5, wherein the titanium ligand and the black phosphorus are at a molar ratio of between 0.9:1 and 10:1.

23. The method according to claim 22, wherein the titanium ligand and the black phosphorus are at a molar ratio of between 3:1 and 10:1.

24. The method according to claim 7, wherein the polar aprotic solvent comprises one or more of N-methylpyrrolidone, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, ethyl acetate and acetone.

25. The method according to claim 7, wherein the polar protic solvent comprises one or more of methanol, ethanol, n-propanol, isopropanol, ethylene glycol and butylene glycol.

26. The method according to claim 7, wherein the non-polar solvent comprises methylene chloride and/or trichloromethane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a .sup.1H-NMR spectrum of the titanium ligand (TiL.sub.4, L: p-toluenesulfonate group) produced in Example 1;

(2) FIG. 2 is a .sup.1H-NMR spectrum of the titanium ligand (TiL.sub.4, L: p-toluenesulfonate group)-modified black phosphorus produced in Example 1;

(3) FIG. 3 is a graph of stability test results of an unmodified black phosphorus and a titanium ligand-modified black phosphorus; and

(4) FIG. 4 is a graph of structural characterization of a titanium ligand (TiL.sub.4, L: p-toluenesulfonate group)-modified black phosphorus produced in Example 1.

DETAILED DESCRIPTION OF THE INVENTION

(5) In order to understand the technical features, objects and beneficial effects of the present invention more clearly, the technical solution of the present invention will be described below in details with reference to specific examples and the accompanying drawings. It is understood that the examples intends to illustrate the present invention only, and are not intended to limit the scope of the invention.

EXAMPLE 1

(6) A titanium ligand (TiL.sub.4, L: p-toluenesulfonate group) used in this example is synthesized by the following route:

(7) ##STR00006##

(8) 1.42 g of p-toluenesulfonic acid is dissolved in 10 mL of ethanol, and 5 mL of a solution of titanium tetraisopropoxide in ethanol having a concentration of 3.44 g/mL is slowly added dropwise thereto at 50 C. and stirred at 40 to 70 C. for 1 to 3 hours, followed by cooling to room temperature. The solvent is removed by rotary evaporation, and the remaining solid is titanium p-toluenesulfonate (TiL.sub.4, L: p-toluenesulfonate group). .sup.1H-NMR (D.sub.2O) thereof is shown in the following FIG. 1.

(9) Black phosphorus is modified with the obtained titanium p-toluenesulfonate as described above by the following route, where BP represents black phosphorus, P represents phosphorus atom, the colon : represents lone pair electrons, and BP's P means the phosphorus atom on black phosphorus:

(10) ##STR00007##

(11) 10.8 mg of titanium p-toluenesulfonate (TiL.sub.4, L: p-toluenesulfonate group) is dissolved in 1 mL of NMP (N-methylpyrrolidone) and added to 1 mL NMP solution with 50 g of black phosphorus quantum dots under nitrogen protection and protected from light. The reaction is carried out at 25 C. under nitrogen protection and protected from light for 12 hours, followed by centrifugation at 7000 to 13000 rpm for 10 to 20 minutes. The supernatant is removed, and the solid is redispersed in ultrapure water, to obtain the titanium ligand-modified black phosphorus. .sup.1H-NMR (D.sub.2O) thereof is shown in FIG. 2. As seen from FIG. 2, NMR signals of titanium sulfonates are present, indicating the successful coordination of the titanium sulfonate to the surface of black phosphorus.

EXAMPLE 2

(12) A titanium p-toluenesulfonate (TiL.sub.4, L: p-toluenesulfonate group) is produced in the same manner as in Example 1. 10.8 mg of titanium p-toluenesulfonate (TiL.sub.4, L: p-toluenesulfonate group) is dissolved in 1 mL of DMSO (dimethyl sulfoxide) and added to 1 mL DMF solution with 500 g multilayered black phosphorous nanosheets under nitrogen protection and protected from light. The reaction is carried out at 40 C. under nitrogen protection and protected from light for 24 hours, followed by centrifugation at 7000 to 13000 rpm for 10 to 20 minutes. The supernatant is removed, and the solid is redispersed in ultrapure water, to obtain the titanium ligand-modified black phosphorus. .sup.1H-NMR detection shows that the obtained titanium ligand-modified black phosphorus has NMR signals of titanium sulfonate, indicating the successful coordination of the titanium sulfonate to the surface of black phosphorus.

EXAMPLE 3

(13) ##STR00008##

(14) are produced in the same manner as in Example 1, and are coordinated to the surface of black phosphorus in the same manner as in Example 1. NMR data all indicate that the above-mentioned titanium ligands are successfully coordinated to the surface of black phosphorus.

EXAMPLE 4

(15) Stability of the Titanium Ligand-Modified Black Phosphorus

(16) The stability of black phosphorus can be characterized by stable or unstable absorption of its solution in the UV-visible-near infrared region. If its absorption decreases over time, it is indicated to be slowly oxidized, and if its absorption does not decrease over time, it is structurally stable. Black phosphorus is the most unstable in an aqueous solution, and the stability of the titanium ligand-modified black phosphorus (TiL.sub.4@BP, wherein TiL.sub.4 are

(17) ##STR00009##
respectively) obtained in Example 1 and Example 3 in the water is studied with the monolayer black phosphorus nanosheet (BP) raw materials of Example 1 and Example 3 as controls. The results are shown in the following FIG. 3. As seen from FIG. 3, the absorption of the monolayer black phosphorus nanosheet raw materials in the aqueous solution decreases over time, and the absorption of the titanium ligand-modified black phosphorus in the aqueous solution is very stable, indicating that the black phosphorus is not likely oxidized after modification with the titanium ligand, and the antioxidant capacity is greatly enhanced.

EXAMPLE 5

(18) Structural Characterization of the Titanium Ligand-Modified Black Phosphorus

(19) The antioxidant property and stability of black phosphorus is enhanced after it is modified with the titanium ligand, but another important requirement for surface modification of black phosphorus is no change in the inherent properties of black phosphorus. In this example, the crystal structures of black phosphorus (BP) and the titanium ligand-modified black phosphorus (TiL.sub.4@BP, wherein TiL.sub.4 is

(20) ##STR00010##
)are studied by a transmission electron microscopy. The study is performed by dropping 4 L aqueous solution of a sample onto an ultrathin carbon support membrane and observing the crystal structure with a high-resolution transmission electron microscopy after it is naturally air-dried. It is found that the crystal structure of black phosphorus remains before and after the modification with the titanium ligand. As shown in FIG. 4, neat lattice streaks with a width of about 0.21 nm can be observed on the black phosphorus raw material in the high-resolution transmission electron microscope (FIG. 4 (left), streaks reflect the crystal structure of black phosphorus), while these lattice stripes still can be observed on the titanium ligand-modified black phosphorus in the high-resolution transmission electron microscopy (FIG. 4 (right)), indicating that the structure of the black phosphorus is kept. Furthermore, there are black shadows covered above the streaks in some regions, which are the linked titanium ligands.

(21) Finally, it is to be appreciated that the above examples are only illustrative of the implementation and features of the present invention and are not intended to limit the scope of the invention. Although the invention has been described in detail with reference to the above examples, it will be understood by those of ordinary skill in the art that modification or equivalent substitution may be made to the present invention, and any modification or partial substitution made without departing from the spirit and scope of the invention shall fall within the protection scope of the present invention.