COPPER OXIDE WITH HOLLOW POROUS STRUCTURE, AND PREPARATION METHOD THEREFOR AND USE THEREOF

Abstract

A copper oxide with a hollow porous structure, a preparation method therefor, and a use thereof are provided. The copper oxide with a hollow porous structure is of a hollow octahedral structure, and has a size of 200-400 nm and a specific surface area of 23.5-79.6 m.sup.2/g, where the surface of the octahedron is composed of copper oxide nanoparticles having a size of 14-33 nm, and pore structures are formed among the copper oxide nanoparticles. The copper oxide with the hollow porous structure has good conductivity, high hydrophilicity and good catalytic performance, can substantially reduce the detection potential and greatly improve the detection sensitivity and the anti-interference performance when used for the electrochemical detection of pesticides.

Claims

1. A copper oxide with a hollow and porous structure, wherein the copper oxide with the hollow and porous structure has a hollow octahedral structure, a surface of an octahedron is composed of copper oxide nanoparticles, and the copper oxide nanoparticles have pore structures therebetween.

2. The copper oxide with the hollow and porous structure according to claim 1, wherein the copper oxide with the hollow and porous structure has a size of 200 to 400 nm and a specific surface area of 23.5 to 79.6 m.sup.2/g; and each of the copper oxide nanoparticles has a size of 14 to 33 nm.

3. A method for preparing a copper oxide with a hollow and porous structure, comprising: (1) adding a strong reductant solution into a copper-based metal organic framework solution for a chemical etching to give a precursor; and (2) calcining the precursor in step (1) at a high temperature to give the copper oxide with the hollow and porous structure.

4. The method according to claim 3, wherein a strong reductant in the strong reductant solution in step (1) is selected from one or more of hydrazine hydrate, sodium borohydride, ammonia water, sodium thiosulfate, and oxalic acid; a solvent in the strong reductant solution is water; a mass ratio of the strong reductant to the water is 0.05:1 to 2.5:1; and a time for the chemical etching is 5 min to 12 h.

5. The method according to claim 3, wherein a solvent in the copper-based metal organic framework solution in step (1) is selected from one or more of water, methanol, acetonitrile, N,N-dimethylformamide, and dimethyl sulfoxide; a mass ratio of a copper-based metal organic framework in the copper-based metal organic framework solution to the solvent is (0.01 to 3):(7.857 to 33); and the copper-based metal organic framework is Cu-MOF-199.

6. The method according to claim 3, wherein the high temperature of the calcining in step (2) is 220 to 650? C., and a time is 1 h to 8 h.

7. The method according to claim 3, wherein the method further comprises: before calcining the precursor at the high temperature, washing and vacuum-drying the precursor obtained in step (1).

8. The method according to claim 7, wherein a solution adopted in the washing is selected from one or more of water, methanol-water, chitosan-water, and acetic acid-water; and a temperature of the vacuum-drying is 80? C., and a time is 6 h to 72 h.

9. A method of a use of the copper oxide with the hollow and porous structure according to claim 1 in a field of lithium-ion batteries, hydrogen storage, supercapacitors, electrocatalysis, or sensors; wherein the method comprises: using the copper oxide with the hollow and porous structure as an electrode modification material; or using the copper oxide with the hollow and porous structure for constructing an electrochemical biosensor.

10. An electrochemical biosensor based on an acetylcholinesterase, wherein electrodes of the electrochemical biosensor are modified with the acetylcholinesterase and a copper oxide with a hollow and porous structure; and the electrochemical biosensor is an electrochemical sensor for a pesticide detection.

11. The method of the use of the copper oxide with the hollow and porous structure according to claim 9, wherein the electrochemical biosensor is constructed based on an acetylcholinesterase.

12. The method of the use of the copper oxide with the hollow and porous structure according to claim 9, wherein the copper oxide with the hollow and porous structure has a size of 200 to 400 nm and a specific surface area of 23.5 to 79.6 m.sup.2/g; and each of the copper oxide nanoparticles has a size of 14 to 33 nm.

13. A method of a use of the copper oxide with the hollow and porous structure prepared by the method according to claim 3 in a field of lithium-ion batteries, hydrogen storage, supercapacitors, electrocatalysis, or sensors; wherein the method comprises: using the copper oxide with the hollow and porous structure as an electrode modification material; or using the copper oxide with the hollow and porous structure for constructing an electrochemical biosensor.

14. The method of the use of the copper oxide with the hollow and porous structure according to claim 13, wherein a strong reductant in the strong reductant solution in step (1) is selected from one or more of hydrazine hydrate, sodium borohydride, ammonia water, sodium thiosulfate, and oxalic acid; a solvent in the strong reductant solution is water; a mass ratio of the strong reductant to the water is 0.05:1 to 2.5:1; and a time for the chemical etching is 5 min to 12 h.

15. The method of the use of the copper oxide with the hollow and porous structure according to claim 13, wherein a solvent in the copper-based metal organic framework solution in step (1) is selected from one or more of water, methanol, acetonitrile, N,N-dimethylformamide, and dimethyl sulfoxide; a mass ratio of a copper-based metal organic framework in the copper-based metal organic framework solution to the solvent is (0.01 to 3):(7.857 to 33); and the copper-based metal organic framework is Cu-MOF-199.

16. The method of the use of the copper oxide with the hollow and porous structure according to claim 13, wherein the high temperature of the calcining in step (2) is 220 to 650? C., and a time is 1 h to 8 h.

17. The method of the use of the copper oxide with the hollow and porous structure according to claim 13, wherein the method further comprises: before calcining the precursor at the high temperature, washing and vacuum-drying the precursor obtained in step (1).

18. The method of the use of the copper oxide with the hollow and porous structure prepared by the method according to claim 17, wherein a solution adopted in the washing is selected from one or more of water, methanol-water, chitosan-water, and acetic acid-water; and a temperature of the vacuum-drying is 80? C., and a time is 6 h to 72 h.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 shows the comparison of appearance before and after chemical etching;

[0029] FIG. 2 shows a scanning electron micrograph of the copper oxide with a hollow and porous structure prepared in Example 1 according to the present invention;

[0030] FIG. 3 shows a transmission electron micrograph of the copper oxide with a hollow and porous structure prepared in Example 2 according to the present invention;

[0031] FIG. 4 shows an X-ray diffraction pattern of the copper oxide with a hollow and porous structure prepared in Example 3 according to the present invention;

[0032] FIG. 5 shows an alternating current impedance curve of the copper oxide with a hollow and porous structure prepared in Example 4 according to the present invention modifying a glassy carbon electrode;

[0033] FIG. 6 shows the contact angle of the copper oxide with a hollow and porous structure prepared in Example 5 according to the present invention; and

[0034] FIG. 7 shows a cyclic voltammogram of the copper oxide with a hollow and porous structure prepared in Example 5 according to the present invention modifying a glassy carbon electrode.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] In order to understand the present invention more clearly, the present invention will be further described with reference to the following examples and drawings. The examples are given for the purpose of illustration only and are not intended to limit the present invention in any way. In the examples, all of the reagents and starting materials are commercially available, and the experimental methods without specifying the specific conditions are conventional methods with conventional conditions well known in the art, or conditions suggested by the instrument manufacturer.

[0036] The Cu-MOF-199 used in the examples of the present invention was prepared by the method described in Journal of Hazardous Materials 390 (2020) 122157.

EXAMPLE 1

[0037] (1) 0.01 g of Cu-MOF-199 was uniformly dispersed into 7.857 g of solvent N,N-dimethylformamide. 0.05 g of hydrazine hydrate and 1 g of ultrapure water were mixed well, and the mixture was added slowly to the N,N-dimethylformamide solution while stirring. The mixture was stirred for 12 h for chemical etching. [0038] (2) After the reaction was complete, the product was washed with ultrapure water and centrifuged 3 times each, and dried in vacuum at 80? C. for 72 h. Finally, the dried product was placed in a muffle furnace, and calcined for 8 h at 220? C. to give a copper oxide with a hollow and porous structure.

[0039] As shown in FIG. 2, the prepared copper oxide had a diameter of 200 to 400 nm and a hollow structure with a rough surface of the material, which provided a large surface area, and a specific surface area of 23.5 m.sup.2/g.

EXAMPLE 2

[0040] (1) 3 g of Cu-MOF-199 was uniformly dispersed into 33 g of solvent dimethyl sulfoxide. 2.5 g of sodium borohydride and 1 g of ultrapure water were mixed well, and the mixture was added slowly to the dimethyl sulfoxide solution while stirring. The mixture was stirred for 5 min for chemical etching. [0041] (2) After the reaction was complete, the product was washed with methanol-water and centrifuged 3 times each, and dried in vacuum at 80? C. for 6 h. Finally, the dried product was placed in a muffle furnace, and calcined for 1 h at 650? C. to give a copper oxide with a hollow and porous structure.

[0042] As shown in FIG. 3, the prepared copper oxide with a hollow and porous structure had an octahedral hollow structure. The surface had obvious pores formed by nanoparticles with a size of 14 to 33 nm, which provided abundant active sites. The specific surface area was 79.6 m.sup.2/g.

EXAMPLE 3

[0043] (1) 1 g of Cu-MOF-199 was uniformly dispersed into 15 g of water. 1 g of ammonia water and 1 g of ultrapure water were mixed well, and the mixture was added slowly to the aqueous solution while stirring. The mixture was stirred for 20 min for chemical etching. [0044] (2) After the reaction was complete, the product was washed with chitosan-water and centrifuged 3 times each, and dried in vacuum at 80? C. for 12 h. Finally, the dried product was placed in a muffle furnace, and calcined for 3 h at 350? C. to give a copper oxide with a hollow and porous structure.

[0045] As shown in FIG. 4, the X-ray diffraction pattern of the prepared copper oxide with a hollow and porous structure was consistent with the standard card of copper oxide; the diffraction peaks corresponded to (111), (111), (202), (310), and the like, indicating that the material prepared in the present invention is copper oxide.

EXAMPLE 4

[0046] (1) 2 g of Cu-MOF-199 was uniformly dispersed into 20 g of methanol. 1.5 g of sodium thiosulfate and 1 g of ultrapure water were mixed well, and the mixture was added slowly to the methanol solution while stirring. The mixture was stirred for 6 h for chemical etching. [0047] (2) After the reaction was complete, the product was washed with acetic acid-water and centrifuged 3 times each, and dried in vacuum at 80? C. for 24 h. Finally, the dried product was placed in a muffle furnace, and calcined for 4 h at 480? C. to give a copper oxide with a hollow and porous structure.

[0048] As shown in FIG. 5, after the glassy carbon electrode was modified with the copper oxide with a hollow and porous structure, an electrochemical impedance test was performed on the glassy carbon electrode by using a three-electrode system. In the Nyquist curve, the curve radius of the electrode modified with the copper oxide was much smaller than that of a bare glassy carbon electrode, which reduced the resistance from 900 ? to 10 ?, suggesting that the copper oxide with a hollow and porous structure has excellent conductivity.

EXAMPLE 5

[0049] (1) 2.5 g of Cu-MOF-199 was uniformly dispersed into 25 g of acetonitrile. 0.5 g of oxalic acid and 1 g of ultrapure water were mixed well, and the mixture was added slowly to the acetonitrile solution while stirring. The mixture was stirred for 1.5 h for chemical etching. [0050] (2) After the reaction was complete, the product was washed with methanol-water and centrifuged 3 times each, and dried in vacuum at 80? C. for 48 h. Finally, the dried product was placed in a muffle furnace, and calcined for 6 h at 600? C. to give a copper oxide with a hollow and porous structure.

[0051] As shown in FIG. 6, when the glassy carbon electrode was modified with the hollow octahedral porous copper oxide, the contact angle was only 26.523?, suggesting that the copper oxide has high hydrophilicity.

[0052] As shown in FIG. 7, when a cyclic voltammogram test of acetylthiocholine chloride was performed on a glassy carbon electrode modified with acetylcholinesterase and the copper oxide, the detection potential of the electrode modified with acetylcholinesterase/copper oxide was significantly reduced from 0.68 V to 0.28 V, and compared with an acetylcholinesterase-modified electrode and an existing electrode, the detection potential was greatly reduced in the presence of the copper oxide.

[0053] It is obvious that the above examples are merely illustrative for a clear explanation and are not intended to limit the implementations. Various changes and modifications can be made by those of ordinary skills in the art on the basis of the above description. It is unnecessary and impossible to exhaustively list all the implementations herein. Obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.