SELF-SUPPORTING ELECTROCATALYTIC MATERIAL AND PREPARATION METHOD THEREOF

Abstract

The present disclosure relates to a self-supporting electrocatalytic material and a preparation method thereof, the self-supporting electrocatalytic material is a Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material. The Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material comprises: a foamed copper substrate, and Cu.sub.2O and WO.sub.3 grown in situ on the foamed copper substrate.

Claims

1. A Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material, comprising: a foamed copper substrate, and Cu.sub.2O and WO.sub.3 grown in situ on the foamed copper substrate.

2. The Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material according to claim 1, wherein the total loading capacity of Cu.sub.2O and WO.sub.3 is 0.5 to 4 mg/cm.sup.2.

3. The Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material according to claim 1, wherein the molar ratio of WO.sub.3 and Cu.sub.2O is 1:(0.5 to 1).

4. The Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material according to claim 1, wherein the Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material also includes NiOOH grown in situ on the foamed copper substrate.

5. The Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material according to claim 4, wherein the total loading capacity of NiOOH, Cu.sub.2O, and WO.sub.3 in the Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material is 0.5 to 4 mg/cm.sup.2.

6. The Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material according to claim 4, wherein the molar ratio of WO.sub.3, Cu.sub.2O and NiOOH is 1:(0.5 to 1):(0.01 to 0.05).

7. A preparation method of the Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material of claim 1, comprising: (1) dissolving a tungsten source in absolute ethanol to obtain a first solution; and (2) immersing the foamed copper in a high-pressure reaction kettle containing the first solution, reacting at 100 to 200° C. for 1 to 36 hours, and then centrifuging, washing, and drying to obtain the Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalyst material.

8. A preparation method of the Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material of claim 4, comprising: (1) dissolving a tungsten source in absolute ethanol to obtain a first solution; and (2) immersing the foamed copper grown with NiOOH and Cu.sub.2O in a high-pressure reaction kettle containing the first solution, reacting at 100 to 200° C. for 1 to 36 hours, and then centrifuging, washing, and drying to obtain a NiOOH/Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material.

9. The preparation method according to claim 8, wherein the foamed copper grown with NiOOH and Cu.sub.2O is prepared by: (1) dissolving a nickel source in water to obtain a second solution; and (2) immersing the foamed copper in a high-pressure reaction kettle containing the second solution, reacting at 160 to 200° C. for 6 to 12 hours, and then washing and drying to obtain the foamed copper with NiOOH and Cu.sub.2O.

10. The preparation method according to claim 9, wherein the nickel source is selected from at least one of nickel acetate Ni(CH.sub.3COO).sub.2, nickel oxalate dihydrate NiC.sub.2O.sub.4.2H.sub.2O, nickel chloride hexahydrate NiCl.sub.2.6H.sub.2O, and nickel nitrate hexahydrate NiN.sub.2O.sub.6.6H.sub.2O, the concentration of the nickel source is 0.01 to 5 mol/L, and the volume filling ratio of the high-pressure reaction kettle containing the second solution is 20 to 80%.

11. The preparation method according to claim 7, wherein the tungsten source is selected from at least one of ammonium tungstate (NH.sub.4).sub.6W.sub.7O.sub.24.6H.sub.2O, ammonium paratungstate (NH.sub.4).sub.10[H.sub.2W.sub.12O.sub.42], ammonium metatungstate (NH.sub.4).sub.6H.sub.2W.sub.12O.sub.40, tungsten isopropoxide W(OCH(CH.sub.3).sub.2).sub.6, and tungsten hexachloride WCl.sub.6, and the concentration of the tungsten source in the first solution is 0.01 to 5 mol/L.

12. The preparation method according to claim 7, wherein the volume filling ratio of the high-pressure reaction kettle containing the first solution is 20 to 60%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 shows X-ray diffraction (XRD) spectra of NiOOH/Cu.sub.2O/WO.sub.3/CF, Cu.sub.2O/WO.sub.3/CF and NiOOH/Cu.sub.2O/CF prepared under the conditions of Example 1, Comparative Example 1, and Example 5;

[0036] FIG. 2 shows scanning electron microscope (SEM) photographs of (a-b) NiOOH/Cu.sub.2O/CF and (c-d) Cu.sub.2O/WO.sub.3/CF prepared under the conditions of Comparative Example 1 and Example 5;

[0037] FIG. 3 shows a SEM photograph of NiOOH/Cu.sub.2O/WO.sub.3/CF prepared under the conditions of Example 1;

[0038] FIG. 4 shows a transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) image of NiOOH/Cu.sub.2O/WO.sub.3/CF prepared under the conditions of Example 1;

[0039] FIG. 5 shows a distribution diagram of corresponding elements of NiOOH/Cu.sub.2O/WO.sub.3/CF prepared under the conditions of Example 1;

[0040] FIG. 6 shows the O1s spectra of NiOOH/Cu.sub.2O/WO.sub.3/CF, Cu.sub.2O/WO.sub.3/CF, and NiOOH/Cu.sub.2O/CF prepared under the conditions of Example 1, Comparative Example 1, and Example 5;

[0041] FIG. 7 shows a comparative graph of the electrocatalytic hydrogen production overpotentials at different current densities for NiOOH/Cu.sub.2O/WO.sub.3/CF, Cu.sub.2O/WO.sub.3/CF, NiOOH/Cu.sub.2O/CF, and CF prepared under the conditions of Example 1, Comparative Example 1, and Example 5.

[0042] FIG. 8 shows a Raman spectrum of NiOOH/Cu.sub.2O/WO.sub.3/CF prepared under the conditions of Example 1.

DETAILED DESCRIPTION

[0043] The present disclosure will be further described below through the following embodiments. It should be understood that the following embodiments are only used to illustrate the present disclosure, not to limit the present disclosure.

[0044] In this disclosure, for the first time, NiOOH, Cu.sub.2O and WO.sub.3 are compounded and directly grown on foamed copper by a two-step method to prepare a NiOOH/Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material rich in oxygen defects. Among them, the optimal total loading capacity of NiOOH/Cu.sub.2O/WO.sub.3 is 0.5 to 4 mg/cm.sup.2. The molar ratio of WO.sub.3, Cu.sub.2O, and NiOOH is 1:(0.5 to 1):(0.01 to 0.05).

[0045] The following exemplarily illustrates the preparation method of the NiOOH/Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material.

[0046] Cleaning of the foamed copper substrate. Take a 50 mL beaker, and completely immerse the foamed copper with a length of 3 to 7 cm and a width of 1 to 2 cm into acetone, HCl solution of 2 to 6 mol/L, deionized water, and absolute ethanol in sequence, and carry out ultrasonic treatment for 15 to 30 minutes respectively.

[0047] Preparation of foamed copper grown with NiOOH/Cu.sub.2O. The type, concentration, and reaction temperature of the selected nickel source in the present disclosure are very important. The target product phase that is not suitable for the preparation cannot be synthesized, and the product loading is too large or too small, so that the product is difficult to directly grow on the foamed copper or cause the composite product to fall off from the foamed copper in the subsequent composite synthesis stage.

[0048] The analytically reagent nickel acetate Ni(CH.sub.3COO).sub.2 is added as a nickel source to 20 to 80 mL of deionized water, and stirred for 20 to 60 minutes to form a uniformly mixed solution A. Among them, the nickel source can also be selected from nickel acetate Ni(CH.sub.3COO).sub.2, nickel oxalate dihydrate NiC.sub.2O.sub.4.2H.sub.2O, nickel chloride hexahydrate NiCl.sub.2.6H.sub.2O, and nickel nitrate hexahydrate NiN.sub.2O.sub.6.6H.sub.2O, etc. The concentration of Ni source in the solution A can be 0.01 to 5 mol/L.

[0049] The foamed copper is immersed in a polytetrafluoroethylene-lined autoclave containing the solution A and sealed, and the volume filling ratio keeps between 20% and 80%. Putting the sealed high-pressure reactor into a homogeneous hydrothermal reactor, the temperature parameter can be set to 160 to 200° C., and the reaction time can be 6 to 12 hours.

[0050] After the reaction is completed, cooling to room temperature, and then centrifuging, washing, and drying to obtain foamed copper with NiOOH/Cu.sub.2O grown on the surface. Among them, washing includes washing with deionized water 3 to 5 times. Among them, drying includes putting the washed foamed copper into a 50 to 70° C. vacuum oven and drying for 5 to 8 hours, or putting in a freeze drying oven at −40 to −60° C. for 5 to 8 hours.

[0051] As a tungsten source, analytical reagent ammonium tungstate (NH.sub.4).sub.6W.sub.7O.sub.24.6H.sub.2O is dissolved and added to 20 to 80 mL of absolute ethanol, and stir for 20 to 60 minutes to form a uniformly mixed solution B. Among them, the tungsten source can also be selected from one of ammonium tungstate (NH.sub.4).sub.6W.sub.7O.sub.24.6H.sub.2O, ammonium paratungstate (NH.sub.4).sub.10[H.sub.2W.sub.12O.sub.42]xH.sub.2O, ammonium metatungstate (NH.sub.4).sub.6H.sub.2W.sub.12O.sub.40.XH.sub.2O, and tungsten isopropoxide W(OCH(CH.sub.3).sub.2).sub.6 and tungsten hexachloride WCl.sub.6, etc. The concentration of the tungsten source in the solution B can be 0.01 to 5 mol/L.

[0052] The NiOOH/Cu.sub.2O-grown foamed copper or pure foamed copper is immersed in a polytetrafluoroethylene lined autoclave containing the solution B and sealed, and the volume filling ratio is maintained between 20% and 60%. Putting the sealed high-pressure reactor into a homogeneous hydrothermal reactor, the temperature parameter can be set to 100 to 200° C., and the reaction time can be 1 to 36 hours.

[0053] After the reaction is completed, cooling to room temperature, and then centrifuging, washing, and drying to obtain foamed copper grown with NiOOH/Cu.sub.2O/WO.sub.3 or foamed copper grown with Cu.sub.2O/WO.sub.3. Among them, washing includes washing with deionized water 3 to 5 times. Among them, drying includes putting the washed foamed copper into a vacuum oven at 50 to 70° C. and drying for 5 to 8 hours, or putting in a freeze drying oven at −40 to −60° C. for 5 to 8 hours.

[0054] Hereinafter, the present disclosure will be further described with the following examples. It should be understood that the following examples are used to explain this invention and do not mean to limit the scope of this invention. Any non-essential improvements and modifications made by a person skilled in the art based on this invention all fall into the protection scope of this invention. The specific process parameters below are only exemplary, and a person skilled in the art can choose proper values within an appropriate range according to the description, and are not restricted to the specific values shown below.

Example 1

[0055] (1) Prepared a nickel acetate Ni(CH.sub.3COO).sub.2.4H.sub.2O solution A with a concentration of 0.05 mol/L. Specifically, Ni(CH.sub.3COO).sub.2.4H.sub.2O was added to 40 mL of deionized water and stirred for 30 minutes to form a uniformly mixed solution A;

[0056] (2) Put the solution A into a polytetrafluoroethylene lined autoclave, the volume filling ratio was maintained at 40%;

[0057] (3) Took a 50 mL beaker, and completely immerse the foamed copper with a length of 6 cm and a width of 1 cm into acetone, 3 mol/L HCl solution, deionized water, and absolute ethanol in sequence, and carried out ultrasonic treatment separately for 30 minutes. Put the processed foamed copper into a polytetrafluoroethylene reactor containing the solution A; put the sealed reactor into a homogeneous hydrothermal reactor, the temperature parameter was set to 160° C., and the reaction time was 12 hours;

[0058] (4) After the reaction was completed and cooled to room temperature, the foamed copper after the reaction was taken out and washed with absolute ethanol and deionized water 3 times;

[0059] (5) Prepared a solution B of tungsten hexachloride WCl.sub.6 with a concentration of 0.05 mol/L. Specifically, added WCl.sub.6 to 40 mL of deionized water and stirred it for 30 minutes to form a uniformly mixed solution B;

[0060] (6) Immersed the NiOOH/Cu.sub.2O-grown foamed copper in a polytetrafluoroethylene lined autoclave containing the solution B and sealed it, and the volume filling ratio was maintained at 40%. Put the sealed autoclave into a homogeneous hydrothermal reactor, the temperature parameter was set to 160° C., and the reaction time was 12 hours;

[0061] (7) After the reaction was completed, cooled to room temperature, took out the foamed copper after the reaction, and washed with absolute ethanol and deionized water 3 times. Put it into a 60° C. vacuum oven or a freeze-drying oven to dry for 6 hours to obtain a NiOOH/Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material. The total loading of NiOOH/Cu.sub.2O/WO.sub.3 was 0.86 mg/cm.sup.2. The molar ratio of WO.sub.3 and Cu.sub.2O was 1:0.5. The molar ratio of WO.sub.3, Cu.sub.2O, and NiOOH was 1:0.5:0.01.

Example 2

[0062] (1) Prepared a nickel acetate Ni(CH.sub.3COO).sub.2.4H.sub.2O solution A with a concentration of 1 mol/L. Specifically, Ni(CH.sub.3COO).sub.2.4H.sub.2O was added to 60 mL of deionized water and stirred for 30 minutes to form a uniformly mixed solution A;

[0063] (2) Put the solution A into a polytetrafluoroethylene lined autoclave, the volume filling ratio was maintained at 60%;

[0064] (3) Took a 50 mL beaker, and completely immersed the foamed copper with a length of 6 cm and a width of 2 cm in acetone, 4 mol/L HCl solution, deionized water, and absolute ethanol in sequence, and carried out ultrasonic treatment separately for 30 minutes. Put the processed foamed copper into a polytetrafluoroethylene reactor containing the solution A; put the sealed reactor into a homogeneous hydrothermal reactor, the temperature parameter was set to 200° C., and the reaction time was 12 hours;

[0065] (4) After the reaction was completed and cooled to room temperature, the foamed copper after the reaction was taken out and washed with absolute ethanol and deionized water 3 times.

[0066] (5) Prepared a solution B of ammonium tungstate (NH.sub.4).sub.6W.sub.7O.sub.24.6H.sub.2O with a concentration of 1 mol/L. Specifically, added (NH.sub.4).sub.6W.sub.7O.sub.24.6H.sub.2O to 40 mL of deionized water and stirred it for 30 minutes to form a uniformly mixed solution B;

[0067] (6) Immersed the NiOOH/Cu.sub.2O-grown foamed copper in a polytetrafluoroethylene lined autoclave containing the solution B and sealed it, and the volume filling ratio was maintained at 40%. Put the sealed autoclave into a homogeneous hydrothermal reactor, the temperature parameter was set to 140° C., and the reaction time was 24 hours;

[0068] (7) After the reaction was completed and cooled to room temperature, the foamed copper after the reaction was taken out and washed with absolute ethanol and deionized water 3 times. Put it into a 60° C. vacuum oven or a freeze-drying oven to dry for 6 hours to obtain a NiOOH/Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material. The total loading of NiOOH/Cu.sub.2O/WO.sub.3 in the obtained NiOOH/Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material was 1.5 mg/cm.sup.2. The molar ratio of WO.sub.3, Cu.sub.2O, and NiOOH was 1:0.3:0.03.

Example 3

[0069] (1) Prepared a nickel oxalate dihydrate NiC.sub.2O.sub.4.2H.sub.2O solution A with a concentration of 3 mol/L. Specifically, NiC.sub.2O.sub.4.2H.sub.2O was added to 50 mL of deionized water and stirred for 30 minutes to form a uniformly mixed solution A;

[0070] (2) Put the solution A into a polytetrafluoroethylene lined autoclave, the volume filling ratio was maintained at 50%;

[0071] (3) Took a 50 mL beaker, and completely immersed the foamed copper with a length of 7 cm and a width of 1 cm into acetone, 3 mol/L HCl solution, deionized water, and absolute ethanol in sequence, and carried out ultrasonic treatment separately for 30 minutes. Put the processed foamed copper into a polytetrafluoroethylene reactor containing the solution A; put the sealed reactor into a homogeneous hydrothermal reactor, the temperature parameter was set to 180° C., and the reaction time was 18 hours;

[0072] (4) After the reaction was completed and cooled to room temperature, the foamed copper after the reaction was taken out and washed with absolute ethanol and deionized water for 3 times;

[0073] (5) Prepared a solution B of tungsten hexachloride WCl.sub.6 with a concentration of 4 mol/L. Specifically, added WCl.sub.6 to 60 mL of deionized water and stirred it for 30 minutes to form a uniformly mixed solution B;

[0074] (6) Immersed the NiOOH/Cu.sub.2O-grown foamed copper in a polytetrafluoroethylene lined autoclave containing the solution B and sealed it, and the volume filling ratio was maintained at 60%. Put the sealed autoclave into a homogeneous hydrothermal reactor, the temperature parameter was set to 140° C., and the reaction time was 30 hours;

[0075] (7) After the reaction was completed, cooled to room temperature, took out the foamed copper after the reaction, and washed with absolute ethanol and deionized water 3 times. Put it into a 60° C. vacuum oven or a freeze-drying oven to dry for 6 hours to obtain a NiOOH/Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material. The total loading of NiOOH/Cu.sub.2O/WO.sub.3 was 3 mg/cm.sup.2. The molar ratio of WO.sub.3, Cu.sub.2O, and NiOOH was 1:0.6:0.05.

Example 4

[0076] (1) Prepared a nickel nitrate hexahydrate NiN.sub.2O.sub.6.6H.sub.2O solution A with a concentration of 4 mol/L. Specifically, NiN.sub.2O.sub.6.6H.sub.2O was added to 80 mL of deionized water and stirred for 30 minutes to form a uniformly mixed solution A;

[0077] (2) Put the solution A into a polytetrafluoroethylene lined autoclave, the volume filling ratio was maintained at 80%;

[0078] (3) Took a 50 mL beaker, and completely immersed the foamed copper with a length of 5 cm and a width of 2 cm into acetone, 6 mol/L HCl solution, deionized water, and absolute ethanol in sequence, and carried out ultrasonic treatment separately for 30 minutes. Put the processed foamed copper into a polytetrafluoroethylene reactor containing the solution A; put the sealed reactor into a homogeneous hydrothermal reactor, the temperature parameter was set to 160° C., and the reaction time was 6 hours;

[0079] (4) After the reaction was completed and cooled to room temperature, the foamed copper after the reaction was taken out and washed with absolute ethanol and deionized water 3 times;

[0080] (5) Prepared a solution B of tungsten isopropoxide W(OCH(CH.sub.3).sub.2).sub.6 with a concentration of 2 mol/L. Specifically, added W(OCH(CH.sub.3).sub.2).sub.6 to 40 mL of deionized water and stirred it for 30 minutes to form a uniformly mixed solution B;

[0081] (6) Immersed the NiOOH/Cu.sub.2O-grown foamed copper in a polytetrafluoroethylene lined autoclave containing the solution B and sealed it, and the volume filling ratio was maintained at 40%. Put the sealed autoclave into a homogeneous hydrothermal reactor, the temperature parameter was set to 160° C., and the reaction time was 24 hours;

[0082] (7) After the reaction was completed and cooled to room temperature, the foamed copper after the reaction was taken out and washed with absolute ethanol and deionized water 3 times. Put it into a 60° C. vacuum oven or a freeze-drying oven to dry for 6 hours to obtain a NiOOH/Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material. The total loading of NiOOH/Cu.sub.2O/WO.sub.3 was 2.8 mg/cm.sup.2. The molar ratio of WO.sub.3 and Cu.sub.2O was 1:0.5. The molar ratio of WO.sub.3, Cu.sub.2O, and NiOOH was 1:0.55:0.03.

Example 5

[0083] The preparation process of the Cu.sub.2O/WO.sub.3/CF electrocatalytic material in Example 5 referring to Example 1, the difference was that the Cu.sub.2O/WO.sub.3 foamed copper was obtained only by a one-step solvothermal method, that is, only the steps of step 5 to step 7 in Example 1 were performed, and what was added in step 6 was the foamed copper that had not grown anything. In the obtained Cu.sub.2O/WO.sub.3/CF self-supporting electrocatalytic material, the loading capacity of Cu.sub.2O/WO.sub.3 was 0.7 mg/cm.sup.2, and the molar ratio of WO.sub.3 and Cu.sub.2O was 1:0.5.

Comparative Example 1

[0084] The preparation process of the NiOOH/Cu.sub.2O/CF self-supporting electrocatalytic material in this comparative example 1 referred to Example 1, the difference was that the foamed copper grown with NiOOH/Cu.sub.2O was obtained only by one-step hydrothermal method, that is, only the steps of 1 to 4 of the Example 1 was performed, the solvothermal reaction process of the steps 5 to 7 was not performed. In the obtained NiOOH/Cu.sub.2O/CF self-supporting electrocatalytic material, the loading capacity of NiOOH/Cu.sub.2O was 0.28 mg/cm.sup.2. The molar ratio of NiOOH and Cu.sub.2O was 0.02:1.

[0085] FIG. 1 shows the X-ray diffraction (XRD) spectra of NiOOH/Cu.sub.2O/WO.sub.3/CF, Cu2O/WO3/CF, and NiOOH/Cu2O/CF prepared under the conditions of Example 1, Comparative Example 1, and Example 5, It can be seen from the figure that no other miscellaneous phases exist in the phase synthesized by the invention.

[0086] FIG. 2 shows the scanning electron microscope (SEM) photographs of NiOOH/Cu.sub.2O/CF and Cu.sub.2O/WO.sub.3/CF prepared under the conditions of Comparative Example 1 and Example 5. It can be seen that the NiOOH/Cu.sub.2O in Comparative Example 1 are large particles formed by agglomeration of many small nanoparticles dispersing in the rough surface structure. The Cu.sub.2O/WO.sub.3 in Example 5 was a composite structure uniformly dispersed by WO.sub.3 nanowires and Cu.sub.2O tetrahedra. These tetrahedrons were of the same size and were entangled by the interwoven nanowire structure at the same time.

[0087] FIG. 3 to FIG. 5 respectively show the SEM photos of NiOOH/Cu.sub.2O/WO.sub.3/CF prepared under the conditions of Example 1, and the element distribution of the tetrahedron and nanowire structure in the NiOOH/Cu.sub.2O/WO.sub.3/CF structure. It can be seen that the microstructure of NiOOH/Cu.sub.2O/WO.sub.3 grown in foamed copper was similar to Cu.sub.2O/WO.sub.3 (FIG. 3). The main elements of the tetrahedron were Cu and O, which further proved that the tetrahedral structure was Cu.sub.2O, the nanowire structure was WO.sub.3 (FIG. 5), combined with XRD; in addition, it can be seen from FIG. 4 that NiOOH and Cu.sub.2O nanoparticles were uniformly dispersed in the material. The heterojunction surface formed by this WO.sub.3/Cu.sub.2O/NiOOH hierarchical structure was very important for the improvement in electrocatalytic performance.

[0088] FIG. 6 shows the O1s spectra of NiOOH/Cu.sub.2O/WO.sub.3/CF, Cu.sub.2O/WO.sub.3/CF, and NiOOH/Cu.sub.2O/CF prepared under the conditions of Example 1, Comparative Example 1, and Example 5. It can be found that the nickel oxide, oxidized cuprous, and tungsten oxide were grown in situ on the foamed copper by a two-step method, and the oxygen defects in the product were significantly increased, which also further proved that NiOOH was effective for the increase in content of oxygen defects, compared with Cu.sub.2O/WO.sub.3/CF and NiOOH/Cu.sub.2O/WO.sub.3/CF composite materials.

[0089] FIG. 7 shows a comparative graph of the electrocatalytic hydrogen production overpotentials at different current densities for NiOOH/Cu.sub.2O/WO.sub.3/CF, Cu.sub.2O/WO.sub.3/CF, NiOOH/Cu.sub.2O/CF, and CF prepared under the conditions of Example 1, Comparative Example 1, and Example 5. The obtained electrocatalytic materials were respectively placed into a neutral electrolyte (1M KH.sub.2PO.sub.4+1M K.sub.2HPO.sub.4) for electrocatalytic testing. It can be seen that the NiOOH/Cu.sub.2O/WO.sub.3/CF electrocatalytic composite material with rich oxygen defect prepared by the present disclosure had the smallest overpotential under different current densities, and its surface had the best hydrogen production performance. At high current densities of 100, 200, 300, 400, and 500 mA/cm.sup.2, its overpotentials were respectively 294, 386, 464, 533, and 589 mV.