A method for preparing TiO2 / CuO composite electrode material
By growing CuO nanosheet arrays in situ on the TiO2 surface and combining micro-arc oxidation and hydrothermal reaction, TiO2/CuO composite electrode materials were prepared, which solved the problems of low specific capacity and poor cycling stability of TiO2 electrode materials and achieved high specific capacity and good cycling stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HEILONGJIANG UNIVERSITY OF SCIENCE AND TECHNOLOGY
- Filing Date
- 2023-03-02
- Publication Date
- 2026-08-04
AI Technical Summary
Existing TiO2 electrode materials have low specific capacity, and their cycling stability is poor due to the volume expansion effect after being combined with CuO.
TiO2/CuO composite electrode materials were prepared by in-situ growth of CuO nanosheet arrays on TiO2 surface, combined with micro-arc oxidation and hydrothermal reaction. The porosity in the CuO nanosheet array was used to reduce the volume expansion effect and improve the specific capacity and cycle stability of the material.
It significantly improved the specific capacity of TiO2/CuO composite materials and achieved a cycle stability of 90%, which is better than the 65% of the traditional nano-CuO modification method.
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Figure CN116072852B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for preparing an electrode material. Background Technology
[0002] In today's market, lithium batteries are widely used in various electronic devices due to their higher energy density, longer cycle life, higher power density, and stronger environmental friendliness. The anode material, as a crucial component of lithium batteries, directly impacts the overall battery performance. TiO2, as a good transition metal oxide anode material, possesses excellent cycle stability, good safety, abundant natural resources, and low environmental impact. However, due to its poor ion diffusion ability, the volume expansion effect of TiO2 results in an actual specific capacity far lower than its theoretical specific capacity of 335 mAh / g. CuO, also a transition metal oxide, boasts a theoretical specific capacity as high as 670 mAh / g, but it also exhibits a significant volume expansion effect. Current research on composite materials mainly involves modifying and coating TiO2 particles with nano-CuO, but this still cannot effectively suppress the volume expansion effect of CuO. Although the specific capacity of the composite material is improved, its cycle stability remains unsatisfactory. Summary of the Invention
[0003] The purpose of this invention is to solve the problems of low specific capacity of existing TiO2 electrode materials and poor cycle stability of TiO2 / CuO composite materials due to volume expansion effect after being combined with CuO materials, and to provide a method for preparing TiO2 / CuO composite electrode materials.
[0004] A method for preparing a TiO2 / CuO composite electrode material is carried out according to the following steps:
[0005] I. Preprocessing:
[0006] First, the pure titanium is degreased, then cleaned and dried to obtain pretreated pure titanium.
[0007] II. Micro-arc oxidation:
[0008] Pretreated pure titanium was placed in a micro-arc oxidation electrolyte for micro-arc oxidation, and a TiO2 micro-arc oxidation film was generated in situ on the surface of pure titanium to obtain TiO2 material.
[0009] III. Preparation of TiO2 / Cu precursor composite materials:
[0010] TiO2 material was sequentially cleaned, dried, degreased, sensitized, activated, and reduced, and finally placed in a chemical plating solution for chemical plating to obtain TiO2 / Cu precursor composite material.
[0011] IV. The TiO2 / Cu precursor composite material is placed in an alkaline solution and then subjected to a hydrothermal reaction to obtain the TiO2 / CuO composite electrode material.
[0012] The beneficial effects of this invention are:
[0013] The method of this invention can grow CuO nanosheet arrays in situ on the TiO2 surface, which can effectively improve the specific capacity of TiO2 material. Furthermore, the porosity between the nanosheets in the CuO nanosheet array can effectively reduce the volume expansion effect of CuO material, thereby improving the cycling stability of the TiO2 / CuO composite material. Specifically:
[0014] 1. Pure titanium was subjected to micro-arc oxidation to prepare TiO2 material, followed by chemical plating, hydrothermal reaction, and vacuum drying to grow an array of CuO nanosheets with excellent bonding in situ. The specific capacity was 426 mAh / g, which was significantly improved compared with TiO2.
[0015] Second, compared with the technique of modifying TiO2 particles with nano-CuO and then coating them to obtain TiO2 / CuO composite materials, the present invention uses the technique of growing CuO nanosheet arrays in situ on the TiO2 surface, thereby obtaining excellent performance with high specific capacity, small volume expansion effect, and cycle stability of 90%. In contrast, the TiO2 / CuO composite material obtained by modifying TiO2 particles with nano-CuO and then coating them has a small specific capacity, a large volume expansion effect, and a cycle stability of only 65%.
[0016] The present invention provides a TiO2 / CuO composite electrode material. Attached Figure Description
[0017] Figure 1 The image is a scanning electron microscope image of the TiO2 / CuO composite electrode material prepared in Example 1, magnified 50,000 times.
[0018] Figure 2 The graph shows the cycling performance of the TiO2 / CuO composite electrode material prepared in Example 1 after 100 cycles.
[0019] Figure 3 This is a scanning electron microscope image of the TiO2 / CuO composite electrode material prepared in Example 2, magnified 50,000 times.
[0020] Figure 4 This is a scanning electron microscope image of the TiO2 / CuO composite electrode material prepared in Example 3, magnified 50,000 times. Detailed Implementation
[0021] Specific Implementation Method 1: This implementation method describes a method for preparing a TiO2 / CuO composite electrode material, which is specifically completed according to the following steps:
[0022] I. Preprocessing:
[0023] First, the pure titanium is degreased, then cleaned and dried to obtain pretreated pure titanium.
[0024] II. Micro-arc oxidation:
[0025] Pretreated pure titanium was placed in a micro-arc oxidation electrolyte for micro-arc oxidation, and a TiO2 micro-arc oxidation film was generated in situ on the surface of pure titanium to obtain TiO2 material.
[0026] III. Preparation of TiO2 / Cu precursor composite materials:
[0027] TiO2 material was sequentially cleaned, dried, degreased, sensitized, activated, and reduced, and finally placed in a chemical plating solution for chemical plating to obtain TiO2 / Cu precursor composite material.
[0028] IV. The TiO2 / Cu precursor composite material is placed in an alkaline solution and then subjected to a hydrothermal reaction to obtain the TiO2 / CuO composite electrode material.
[0029] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the degreasing steps in steps one and three are as follows: the material is immersed in a mixed solution of sodium carbonate and sodium phosphate, and then kept at a temperature of 30℃ to 80℃ for 3 to 30 minutes to complete the degreasing; the sodium carbonate content in the mixed solution is 15 g / L to 40 g / L, the sodium phosphate content is 20 g / L to 50 g / L, and the solvent is water; the cleaning in steps one and three is ultrasonic cleaning using deionized water; the drying temperature in steps one and three is 30℃ to 100℃. Other steps are the same as in Specific Implementation Method One.
[0030] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the micro-arc oxidation electrolyte mentioned in step two is composed of sodium phosphate, sodium silicate, disodium ethylenediaminetetraacetate, and deionized water, wherein the concentration of sodium phosphate is 20 g / L to 40 g / L, the concentration of sodium silicate is 10 g / L to 20 g / L, and the concentration of disodium ethylenediaminetetraacetate is 1 g / L to 8 g / L. Other steps are the same as in Specific Implementation Method One or Two.
[0031] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: the duty cycle of the micro-arc oxidation in step two is 5% to 30%, the frequency of the micro-arc oxidation is 400Hz to 1200Hz, the current of the micro-arc oxidation is 2A to 5A, and the time of the micro-arc oxidation is constant current oxidation for 1min to 10min. Other steps are the same as in Specific Implementation Methods One to Three.
[0032] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the specific steps of the sensitization treatment in step three are as follows: The degreased TiO2 material is placed in a sensitization solution and immersed at 10℃~40℃ for 0.5min~10min, then washed with deionized water and dried. The sensitization solution is prepared by completely dissolving stannous chloride in hydrochloric acid, then adding deionized water to obtain the sensitization solution. The concentration of stannous chloride in the sensitization solution is 5g / L~20g / L, and the concentration of hydrochloric acid is 20mL / L~60mL / L. The mass fraction of the hydrochloric acid is 37%. Other steps are the same as in Specific Implementation Methods One to Four.
[0033] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the specific steps of the activation treatment in step three are as follows: The sensitized TiO2 material is placed in an activation solution and immersed at 10℃~40℃ for 0.5min~10min, then washed with deionized water and dried. The activation solution is prepared by completely dissolving palladium chloride in anhydrous ethanol, then adding deionized water to obtain the activation solution. The concentration of palladium chloride in the activation solution is 0.1g / L~1g / L, and the concentration of anhydrous ethanol is 200mL / L~500mL / L. Other steps are the same as in Specific Implementation Methods One to Five.
[0034] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the specific steps of the reduction treatment in step three are as follows: The activated TiO2 material is placed in a reduction solution and immersed at 10℃~40℃ for 0.5min~10min, then washed with deionized water and dried. The reduction solution is prepared by completely dissolving sodium hypophosphite in deionized water to obtain the reduction solution. The concentration of sodium hypophosphite in the reduction solution is 20g / L~40g / L. Other steps are the same as in Specific Implementation Methods One to Six.
[0035] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that: the specific steps of the chemical plating described in Step Three are as follows: the reduced TiO2 material is placed in a chemical plating solution and chemically plating is performed at 10℃~40℃ for 0.5min~20min, followed by rinsing with deionized water and drying; the chemical plating solution is prepared by mixing potassium sodium tartrate, lactic acid, copper sulfate pentahydrate, anhydrous sodium acetate, sodium hydroxide, formaldehyde, and deionized water to obtain the chemical plating solution; the concentration of potassium sodium tartrate in the chemical plating solution is 20g / L~40g / L, the concentration of lactic acid is 10mL / L~20mL / L, the concentration of copper sulfate pentahydrate is 3g / L~10g / L, the concentration of anhydrous sodium acetate is 10g / L~20g / L, the concentration of sodium hydroxide is 5g / L~10g / L, and the concentration of formaldehyde is 8mL / L~15mL / L; the pH value of the chemical plating solution is 12~14. The other steps are the same as those in Specific Implementation Methods 1 to 7.
[0036] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that the specific steps of the hydrothermal reaction in step four are as follows: The TiO2 / Cu precursor composite material is placed in an alkaline solution and reacted at 75℃ to 95℃ for 1 min to 30 min. Then, it is placed in a vacuum drying oven and vacuum dried at 50℃ to 250℃ for 1 h to 5 h to obtain the TiO2 / CuO composite electrode material. The alkaline solution is prepared by mixing sodium hydroxide, ammonium persulfate, sodium thiosulfate, hydrogen peroxide, and deionized water. The concentration of sodium hydroxide in the alkaline solution is 0.5 mol / L to 5 mol / L, the concentration of ammonium persulfate is 0.01 mol / L to 0.2 mol / L, the concentration of sodium thiosulfate is 0.02 mol / L to 0.05 mol / L, and the concentration of hydrogen peroxide is 1 mL / L to 5 mL / L. The other steps are the same as in Specific Implementation Methods One to Eight.
[0037] Specific Implementation Method Ten: The difference between this implementation method and Specific Implementation Methods One through Eight is that: the TiO2 / CuO composite electrode material mentioned in step four is CuO grown in situ on the surface of TiO2 material, and the microstructure of the CuO grown in situ on the TiO2 surface is a nanosheet array with a nanosheet length of 100 nm.
[0038] ~200nm, thickness 30nm~50nm. Specific implementation methods one through nine are the same.
[0039] The beneficial effects of the present invention are verified using the following embodiments:
[0040] Example 1: A method for preparing a TiO2 / CuO composite electrode material, specifically completed according to the following steps:
[0041] I. Preprocessing:
[0042] First, the pure titanium is degreased, then cleaned and dried to obtain pretreated pure titanium.
[0043] II. Micro-arc oxidation:
[0044] Pretreated pure titanium was placed in a micro-arc oxidation electrolyte for micro-arc oxidation, and a TiO2 micro-arc oxidation film was generated in situ on the surface of pure titanium to obtain TiO2 material.
[0045] III. Preparation of TiO2 / Cu precursor composite materials:
[0046] TiO2 material was sequentially cleaned, dried, degreased, sensitized, activated, and reduced, and finally placed in a chemical plating solution for chemical plating to obtain TiO2 / Cu precursor composite material.
[0047] IV. The TiO2 / Cu precursor composite material is placed in an alkaline solution and then subjected to a hydrothermal reaction to obtain the TiO2 / CuO composite electrode material.
[0048] The specific steps for degreasing in steps one and three are as follows: immerse the material in a mixed solution of sodium carbonate and sodium phosphate, and then keep it at 60°C for 10 minutes to complete the degreasing process; the mixed solution of sodium carbonate and sodium phosphate contains 20 g / L of sodium carbonate and 30 g / L of sodium phosphate, and the solvent is water; the cleaning in steps one and three involves ultrasonic cleaning with deionized water for 1 minute; the drying temperature in steps one and three is 80°C, and the drying time is 30 minutes.
[0049] The micro-arc oxidation electrolyte mentioned in step two is composed of sodium phosphate, sodium silicate, disodium ethylenediaminetetraacetate and deionized water, wherein the concentration of sodium phosphate is 30 g / L, the concentration of sodium silicate is 15 g / L and the concentration of disodium ethylenediaminetetraacetate is 5 g / L.
[0050] In step two, the duty cycle of micro-arc oxidation is 15%, the frequency of micro-arc oxidation is 800Hz, the current of micro-arc oxidation is 3A, and the time of micro-arc oxidation is constant current oxidation for 3min.
[0051] The specific steps of the sensitization treatment in step three are as follows: The degreased TiO2 material is placed in a sensitization solution and soaked at 30°C for 5 minutes, then washed with deionized water and dried. The sensitization solution is prepared by completely dissolving stannous chloride in hydrochloric acid, then adding deionized water to obtain the sensitization solution. The concentration of stannous chloride in the sensitization solution is 10 g / L, and the concentration of hydrochloric acid is 30 mL / L. The mass fraction of the hydrochloric acid is 37%.
[0052] The specific steps of the activation treatment described in step three are as follows: the sensitized TiO2 material is placed in an activation solution and soaked at 30°C for 5 minutes, then washed with deionized water and dried; the activation solution is prepared by completely dissolving palladium chloride in anhydrous ethanol, then adding deionized water to obtain the activation solution; the concentration of palladium chloride in the activation solution is 0.8 g / L, and the concentration of anhydrous ethanol is 500 mL / L;
[0053] The specific steps of the reduction treatment described in step three are as follows: the activated TiO2 material is placed in a reduction solution and soaked at 30°C for 5 minutes, then washed with deionized water and dried; the reduction solution is prepared by completely dissolving sodium hypophosphite in deionized water to obtain the reduction solution; the concentration of sodium hypophosphite in the reduction solution is 30 g / L.
[0054] The specific steps of the electroless plating described in step three are as follows: The reduced TiO2 material is placed in the electroless plating solution and electroless plating is performed at 30°C for 3 minutes, followed by rinsing with deionized water and drying. The electroless plating solution is prepared by mixing potassium sodium tartrate, lactic acid, copper sulfate pentahydrate, anhydrous sodium acetate, sodium hydroxide, formaldehyde, and deionized water. The concentration of potassium sodium tartrate in the electroless plating solution is 40 g / L, the concentration of lactic acid is 10 mL / L, the concentration of copper sulfate pentahydrate is 5 g / L, the concentration of anhydrous sodium acetate is 15 g / L, the concentration of sodium hydroxide is 10 g / L, and the concentration of formaldehyde is 15 mL / L. The pH value of the electroless plating solution is 13–14.
[0055] The specific steps of the hydrothermal reaction described in step four are as follows: the TiO2 / Cu precursor composite material is placed in an alkaline solution and reacted at 80°C for 5 minutes, then placed in a vacuum drying oven and vacuum dried at 100°C for 2 hours to obtain the TiO2 / CuO composite electrode material; the alkaline solution is prepared by mixing sodium hydroxide, ammonium persulfate, sodium thiosulfate, hydrogen peroxide and deionized water to obtain the alkaline solution; the concentration of sodium hydroxide in the alkaline solution is 1 mol / L, the concentration of ammonium persulfate is 0.05 mol / L, the concentration of sodium thiosulfate is 0.03 mol / L, and the concentration of hydrogen peroxide is 2 mL / L.
[0056] Example 2: This example differs from Example 1 in that: in step four, the TiO2 / Cu precursor composite material is placed in an alkaline solution and reacted at 80°C for 10 minutes, and then placed in a vacuum drying oven and vacuum dried at 50°C for 2 hours to obtain the TiO2 / CuO composite electrode material.
[0057] Example 3: This example differs from Example 1 in that: in step 4, the TiO2 / Cu precursor composite material is placed in an alkaline solution and reacted at 80°C for 10 minutes, and then placed in a vacuum drying oven and vacuum dried at 100°C for 3 hours to obtain the TiO2 / CuO composite electrode material.
[0058] Figure 1 The image is a scanning electron microscope image of the TiO2 / CuO composite electrode material prepared in Example 1, magnified 50,000 times.
[0059] Depend on Figure 1 It can be seen that a CuO nanosheet array is completely grown on the TiO2 surface. The nanosheets are about 300 nm long and about 50 nm thick, and the nanosheet array is neat, uniform and grows upright.
[0060] Figure 2 The graph shows the cycling performance of the TiO2 / CuO composite electrode material prepared in Example 1 after 100 cycles.
[0061] Depend on Figure 2 It can be seen that the TiO2 / CuO composite electrode material prepared in Example 1 has a first-cycle specific capacity of 426 mAh / g, and after 100 cycles, the capacity is still 90%, which shows good cycling stability.
[0062] Figure 3 This is a scanning electron microscope image of the TiO2 / CuO composite electrode material prepared in Example 2, magnified 50,000 times.
[0063] Depend on Figure 3 It can be seen that the CuO nanosheets on the TiO2 surface are still in the "budding" state, and most of the CuO is still in the form of particles and has not fully grown into a nanosheet array. The TiO2 / CuO composite electrode material prepared in Example 2 has an initial specific capacity of 396 mAh / g, but after 100 cycles, the capacity decays to 317 mAh / g, with a capacity retention rate of 80%.
[0064] Figure 4 This is a scanning electron microscope image of the TiO2 / CuO composite electrode material prepared in Example 3, magnified 50,000 times.
[0065] Depend on Figure 4 It can be seen that with prolonged vacuum drying, the CuO nanosheets on the TiO2 surface have become elongated due to overgrowth, and some CuO nanosheets have become interconnected, existing in a layered manner, thus completely destroying the CuO nanosheet array. The TiO2 / CuO composite electrode material prepared in Example 3 exhibits an initial specific capacity of 254 mAh / g, but after 100 cycles, the capacity decays to 135 mAh / g, with a capacity retention of only 53%.
Claims
1. A method for preparing a TiO2 / CuO composite electrode material, characterized in that... The preparation method is specifically carried out according to the following steps: I. Preprocessing: First, the pure titanium is degreased, then cleaned and dried to obtain pretreated pure titanium. II. Micro-arc oxidation: Pretreated pure titanium was placed in a micro-arc oxidation electrolyte for micro-arc oxidation, and a TiO2 micro-arc oxidation film was generated in situ on the surface of pure titanium to obtain TiO2 material. III. Preparation of TiO2 / Cu precursor composite materials: TiO2 material was sequentially cleaned, dried, degreased, sensitized, activated, and reduced, and finally placed in a chemical plating solution for chemical plating to obtain TiO2 / Cu precursor composite material. IV. The TiO2 / Cu precursor composite material is placed in an alkaline solution and then subjected to a hydrothermal reaction to obtain the TiO2 / CuO composite electrode material.
2. The method for preparing a TiO2 / CuO composite electrode material according to claim 1, characterized in that... The specific steps for degreasing described in steps one and three are as follows: immerse the material in a mixed solution of sodium carbonate and sodium phosphate, and then maintain the temperature at 30℃~80℃ for 3min~30min to complete the degreasing; the sodium carbonate content in the mixed solution of sodium carbonate and sodium phosphate is 15g / L~40g / L, the sodium phosphate content is 20g / L~50g / L, and the solvent is water; the cleaning described in steps one and three is ultrasonic cleaning using deionized water; the drying temperature described in steps one and three is 30℃~100℃.
3. The method for preparing a TiO2 / CuO composite electrode material according to claim 1, characterized in that... The micro-arc oxidation electrolyte mentioned in step two is composed of sodium phosphate, sodium silicate, disodium ethylenediaminetetraacetate and deionized water, wherein the concentration of sodium phosphate is 20 g / L to 40 g / L, the concentration of sodium silicate is 10 g / L to 20 g / L, and the concentration of disodium ethylenediaminetetraacetate is 1 g / L to 8 g / L.
4. The method for preparing a TiO2 / CuO composite electrode material according to claim 1, characterized in that... In step two, the duty cycle of micro-arc oxidation is 5% to 30%, the frequency of micro-arc oxidation is 400Hz to 1200Hz, the current of micro-arc oxidation is 2A to 5A, and the time of micro-arc oxidation is constant current oxidation for 1min to 10min.
5. The method for preparing a TiO2 / CuO composite electrode material according to claim 1, characterized in that... The specific steps of the sensitization treatment in step three are as follows: The degreased TiO2 material is placed in a sensitization solution and immersed at 10℃~40℃ for 0.5min~10min, then rinsed with deionized water and dried. The sensitization solution is prepared by completely dissolving stannous chloride in hydrochloric acid, then adding deionized water to obtain the sensitization solution. The concentration of stannous chloride in the sensitization solution is 5g / L~20g / L, and the concentration of hydrochloric acid is 20mL / L~60mL / L. The mass fraction of the hydrochloric acid is 37%.
6. The method for preparing a TiO2 / CuO composite electrode material according to claim 1, characterized in that... The specific steps of the activation treatment described in step three are as follows: the sensitized TiO2 material is placed in an activation solution and soaked at 10℃~40℃ for 0.5min~10min, and then washed with deionized water and dried; the activation solution is prepared by completely dissolving palladium chloride in anhydrous ethanol, and then adding deionized water to obtain the activation solution; the concentration of palladium chloride in the activation solution is 0.1g / L~1g / L, and the concentration of anhydrous ethanol is 200mL / L~500mL / L.
7. The method for preparing a TiO2 / CuO composite electrode material according to claim 1, characterized in that... The specific steps of the reduction treatment described in step three are as follows: the activated TiO2 material is placed in a reduction solution and soaked at 10℃~40℃ for 0.5min~10min, and then washed with deionized water and dried; the reduction solution is prepared by completely dissolving sodium hypophosphite in deionized water to obtain a reduction solution; the concentration of sodium hypophosphite in the reduction solution is 20g / L~40g / L.
8. The method for preparing a TiO2 / CuO composite electrode material according to claim 1, characterized in that... The specific steps of the electroless plating described in step three are as follows: The reduced TiO2 material is placed in the electroless plating solution and electroless plating is performed at 10℃~40℃ for 0.5min~20min, followed by rinsing with deionized water and drying. The electroless plating solution is prepared by mixing potassium sodium tartrate, lactic acid, copper sulfate pentahydrate, anhydrous sodium acetate, sodium hydroxide, formaldehyde, and deionized water. The concentration of potassium sodium tartrate in the electroless plating solution is 20g / L~40g / L, the concentration of lactic acid is 10mL / L~20mL / L, the concentration of copper sulfate pentahydrate is 3g / L~10g / L, the concentration of anhydrous sodium acetate is 10g / L~20g / L, the concentration of sodium hydroxide is 5g / L~10g / L, and the concentration of formaldehyde is 8mL / L~15mL / L. The pH value of the electroless plating solution is 12~14.
9. The method for preparing a TiO2 / CuO composite electrode material according to claim 1, characterized in that... The specific steps of the hydrothermal reaction described in step four are as follows: the TiO2 / Cu precursor composite material is placed in an alkaline solution and reacted at 75℃~95℃ for 1min~30min, then placed in a vacuum drying oven and vacuum dried at 50℃~250℃ for 1h~5h to obtain the TiO2 / CuO composite electrode material; the alkaline solution is prepared by mixing sodium hydroxide, ammonium persulfate, sodium thiosulfate, hydrogen peroxide and deionized water to obtain the alkaline solution; the concentration of sodium hydroxide in the alkaline solution is 0.5mol / L~5mol / L, the concentration of ammonium persulfate is 0.01mol / L~0.2mol / L, the concentration of sodium thiosulfate is 0.02mol / L~0.05mol / L, and the concentration of hydrogen peroxide is 1mL / L~5mL / L.
10. The method for preparing a TiO2 / CuO composite electrode material according to claim 1, characterized in that... The TiO2 / CuO composite electrode material mentioned in step four is CuO grown in situ on the surface of TiO2 material. The microstructure of CuO grown in situ on the TiO2 surface is a nanosheet array with a length of 100nm to 200nm and a thickness of 30nm to 50nm.