Preparation method of ZnV double-doped CuWO4 photoelectrocatalysis film
By using a method for preparing Zn and V co-doped CuWO4 thin films, the problem of easy recombination of photogenerated electron-hole pairs in CuWO4 was solved, which improved the efficiency of photoelectrochemical water splitting, broadened the visible light absorption range, and optimized the energy level matching.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-14
- Publication Date
- 2026-04-14
AI Technical Summary
CuWO4 photogenerated electron-hole pairs easily recombine, resulting in low efficiency of photoelectrochemical water splitting. Existing research is scarce, and research on improving this efficiency through dual doping is even less so.
A method for preparing Zn and V co-doped CuWO4 thin films was adopted, including hydrothermal synthesis and heat treatment steps, and the band position and separation of photogenerated electron-hole pairs were optimized.
It increases photocurrent density, broadens the visible light absorption range, optimizes energy level matching, and enhances photoelectrocatalytic performance.
Smart Images
Figure CN121853003A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of photoelectrocatalytic materials technology, specifically relating to a method for preparing a Zn&V dual-doped CuWO4 photoelectrocatalytic thin film. Background Technology
[0002] Photoelectrocatalytic hydrogen production using semiconductor materials has become a current research hotspot. Photoelectrocatalytic water splitting utilizes semiconductor materials to absorb sunlight to generate hydrogen, realizing the conversion of solar energy into chemical energy. In the photoelectrocatalytic water splitting process, the properties of the semiconductor material determine the decomposition efficiency of the entire process. Ideal photoelectrocatalytic materials must include the following characteristics: (1) the semiconductor material must have a suitable band gap and band position; (2) the semiconductor material must have good stability in the photoelectrocatalytic water splitting process; (3) the semiconductor material must be inexpensive and suitable for large-scale production. CuWO4 is an n-type semiconductor material with a band gap of about 2.3 eV, which can absorb visible light less than 540 nm. However, the photogenerated electron-hole pairs of CuWO4 are prone to recombination, resulting in its actual efficiency being far lower than the ideal efficiency. Therefore, researchers need to find an effective method to overcome this problem and improve the performance of CuWO4 photoelectrocatalytic water splitting. Zn & V double-doped CuWO4 can further improve the response of CuWO4 to sunlight. On the other hand, it can change the band position of CuWO4, accelerate the transmission and separation of photogenerated electron-hole pairs, and thus improve the lack of easy recombination of photogenerated electron-hole pairs in CuWO4.
[0003] To date, there are few reports on the application of CuWO4 in photoelectrochemical water splitting, and even fewer studies on improving the recombination of photogenerated electron-hole pairs in CuWO4 using dual doping. Therefore, the use of Zn & V dual-doped CuWO4 thin films for photoelectrochemical water splitting to produce hydrogen is a worthy research topic. Summary of the Invention
[0004] This invention addresses the problem of easy recombination of photogenerated electron-hole pairs in CuWO4 semiconductors and improves the performance of CuWO4 photoelectrocatalytic water splitting for hydrogen production. This invention proposes a method for preparing Zn&V dual-doped CuWO4 thin films for photoelectrocatalytic water splitting for hydrogen production.
[0005] The technical solution adopted in this invention is a method for preparing a Zn&V dual-doped CuWO4 photoelectrocatalytic thin film, comprising the following steps:
[0006] (1) First, dissolve Na2WO4·2H2O and NH4VO3 in deionized water and stir magnetically for 15 min at room temperature. Then, add hydrochloric acid to the above solution and stir magnetically for 20 min until no more yellow precipitate is formed. Mix ammonium oxalate into the above suspension. Stir until the solution becomes clear to obtain the precursor solution.
[0007] (2) Place the cleaned and prepared FTO substrate with the conductive side facing down in the inner liner of the high-pressure reactor and carry out hydrothermal synthesis at a certain temperature for a period of time. After the high-pressure reactor cools down to room temperature, take out the FTO substrate, rinse it several times with deionized water, and dry it in an oven at 60°C.
[0008] (3) Using aqueous solutions of CuCl2 and ZnCl2 as precursor solutions, the mixture was magnetically stirred for 20 min at room temperature.
[0009] (4) The obtained V-doped WO3 / FTO was tilted at a certain angle (45°) onto the inner wall beforehand. The solution was then transferred to a 25 ml stainless steel autoclave lined with polytetrafluoroethylene. The autoclave was then sealed and heated at 170℃~190℃ for 8h~12h. After the autoclave cooled naturally to room temperature, the obtained sample was slowly and carefully washed several times with alcohol and distilled water, and then dried in an oven at 60℃.
[0010] (5) Place the FTO prepared in step (4) in a box-type resistance furnace for heat treatment, and take it out after cooling to room temperature.
[0011] Preferably, the process parameters for step (1) are as follows: dissolve 0.1g–0.4g Na₂WO₄ and 0.01g–0.04g NH₄VO₃ in 30ml–60ml of deionized water, with the NH₄VO₃ incorporation ratio being 2%–10%. Stir magnetically at room temperature for 15min, then add 6ml–12ml HCl (3M) to adjust the pH of the solution, and continue stirring for 20min until no more yellow precipitate forms. Then add 0.2g–0.5g ammonium oxalate, and stir the solution until clear to obtain the precursor solution.
[0012] Preferably, the process parameters for step (2) are as follows: the cleaned and prepared FTO is placed with the conductive side facing down in the inner liner of the high-pressure reactor, the precursor solution prepared in step (1) is poured in, a hydrothermal reaction is carried out, the FTO is taken out after cooling to room temperature and washed with deionized water, and dried at 60°C to obtain a V-doped WO3 film.
[0013] Preferably, the process parameters for step (3) are as follows: 0.1g to 0.4g CuCl2 and 0.01g to 0.04g ZnCl2 are dissolved in deionized water, and the ZnCl2 doping ratio is 2% to 10%. The precursor solution is prepared by magnetic stirring at room temperature.
[0014] Preferably, the process parameters for step (4) are as follows: the V-doped WO3 / FTO obtained in advance is placed with the conductive side facing down in the inner liner of the high-pressure reactor, the precursor liquid prepared in step (3) is poured in, and a hydrothermal reaction is carried out at 160℃~200℃ for 6h~10h. After cooling to room temperature, the FTO is taken out and washed with deionized water, and then dried in an oven.
[0015] Preferably, the process parameters for step (5) are as follows: the FTO prepared in step (4) is placed in a box-type resistance furnace for heat treatment, calcined at 450℃~550℃ for 1h~3h, and then cooled to room temperature before being taken out to prepare a Zn&V double-doped CuWO4 photoelectrocatalytic thin film.
[0016] The beneficial effects of the method for preparing Zn&V dual-doped CuWO4 photoelectrocatalytic thin films provided by this invention are:
[0017] (1) The Zn&V double-doped CuWO4 film obtained in this invention was tested and found that the photocurrent density of the Zn&V double-doped CuWO4 film was improved compared with that of the pure CuWO4 film.
[0018] (2) The Zn&V double-doped CuWO4 thin film obtained by the present invention can effectively broaden the visible light absorption range.
[0019] (3) The Zn&V double-doped CuWO4 thin film prepared by the present invention can optimize energy level matching.
[0020] (4) The preparation method provided by the present invention is simple, environmentally friendly, low in cost, and has high photoelectrocatalytic performance. Attached Figure Description
[0021] Figure 1 This is a linear scanning voltammetry of the Zn&V double-doped CuWO4 thin film of the present invention. Detailed Implementation
[0022] The following embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way.
[0023] Example 1
[0024] A method for preparing a Zn&V dual-doped CuWO4 photoelectrocatalytic thin film includes the following steps:
[0025] (1) Dissolve 0.1 g Na2WO4 and 0.01 g NH4VO3 in 30 ml of deionized water and stir magnetically for 15 min at room temperature. Then add 6 ml HCl (3 M) to adjust the pH of the solution and continue stirring for 20 min until no more yellow precipitate is formed. Then add 0.2 g ammonium oxalate and stir the solution until clear to obtain the precursor solution.
[0026] (2) Place the cleaned and prepared FTO with the conductive side facing down in the inner liner of the high-pressure reactor, pour in the precursor solution prepared in step (1), and perform a hydrothermal reaction at 160°C for 6 hours. After cooling to room temperature, remove the FTO and wash it with deionized water. Dry it at 60°C to obtain a WO3 film.
[0027] (3) Dissolve 0.1g CuCl2 and 0.01g ZnCl2 in deionized water and stir magnetically at room temperature to prepare CuCl2 solution.
[0028] (4) Place the V-doped WO3 / FTO with the conductive side facing down in the inner liner of the high-pressure reactor, pour in the precursor liquid prepared in step (3), perform a hydrothermal reaction at 170°C for 8 hours, cool to room temperature, remove the FTO and wash with deionized water, and dry in an oven.
[0029] (5) The FTO prepared in step (4) was placed in a box-type resistance furnace at 450°C for 1 hour for heat treatment. After cooling to room temperature, it was taken out to prepare a Zn&V double-doped CuWO4 thin film.
[0030] Example 2
[0031] A method for preparing a Zn&V dual-doped CuWO4 photoelectrocatalytic thin film includes the following steps:
[0032] (1) Dissolve 0.2g Na2WO4 and 0.02g NH4VO3 in 40ml deionized water and stir magnetically for 15min at room temperature. Then add 8ml HCl (3M) to adjust the pH of the solution and continue stirring for 20min until no more yellow precipitate is formed. Then add 0.3g ammonium oxalate and stir the solution until clear to obtain the precursor solution.
[0033] (2) Place the cleaned and prepared FTO with the conductive side facing down in the inner liner of the high-pressure reactor, pour in the precursor solution prepared in step (1), and perform a hydrothermal reaction at 180°C for 8 hours. After cooling to room temperature, remove the FTO and wash it with deionized water. Dry it at 60°C to obtain a WO3 film.
[0034] (3) Dissolve 0.2g CuCl2 and 0.02g ZnCl2 in deionized water and stir magnetically at room temperature to prepare CuCl2 solution.
[0035] (4) Place the V-doped WO3 / FTO with the conductive side facing down in the inner liner of the high-pressure reactor, pour in the precursor liquid prepared in step (3), perform a hydrothermal reaction at 180°C for 10 hours, cool to room temperature, remove the FTO and wash with deionized water, and dry in an oven.
[0036] (5) The FTO prepared in step (4) was placed in a box-type resistance furnace at 500°C for 2 hours for heat treatment. After cooling to room temperature, it was taken out to prepare a Zn&V double-doped CuWO4 thin film.
[0037] Example 3
[0038] A method for preparing a Zn&V dual-doped CuWO4 photoelectrocatalytic thin film includes the following steps:
[0039] (1) Dissolve 0.4 g Na2WO4 and 0.04 g NH4VO3 in 60 ml of deionized water and stir magnetically for 15 min at room temperature. Then add 10 ml HCl (3 M) to adjust the pH of the solution and continue stirring for 20 min until no more yellow precipitate is formed. Then add 0.5 g ammonium oxalate and stir the solution until clear to obtain the precursor solution.
[0040] (2) Place the cleaned and prepared FTO with the conductive side facing down in the inner liner of the high-pressure reactor, pour in the precursor solution prepared in step (1), and perform a hydrothermal reaction at 200°C for 10 hours. After cooling to room temperature, remove the FTO and wash it with deionized water. Dry it at 60°C to obtain a WO3 film.
[0041] (3) Dissolve 0.4g CuCl2 and 0.04g ZnCl2 in deionized water and stir magnetically at room temperature to prepare CuCl2 solution.
[0042] (4) Place the V-doped WO3 / FTO with the conductive side facing down in the inner liner of the high-pressure reactor, pour in the precursor liquid prepared in step (3), perform a hydrothermal reaction at 190°C for 12 hours, cool to room temperature, remove the FTO and wash with deionized water, and dry in an oven.
[0043] (5) The FTO prepared in step (4) was placed in a box-type resistance furnace at 550°C for 3 hours for heat treatment. After cooling to room temperature, it was taken out to prepare a Zn&V double-doped CuWO4 thin film.
[0044] The present invention has been described in detail above through embodiments, but the content described is only an exemplary embodiment of the present invention and should not be considered as limiting the scope of the present invention. The scope of protection of the present invention is defined by the claims. Any technical solutions designed by those skilled in the art using the technical solutions described in the present invention, or similar technical solutions designed by those skilled in the art under the inspiration of the technical solutions of the present invention, within the substance and scope of protection of the present invention, to achieve the above-mentioned technical effects, or equivalent changes and improvements made to the scope of the application, should still fall within the patent protection scope of the present invention. It should be noted that, for clarity, some parts and descriptions of processes that are not directly and obviously related to the scope of protection of the present invention but are known to those skilled in the art have been omitted in the description of the present invention.
Claims
1. A method for preparing a Zn&V dual-doped CuWO4 photoelectrocatalytic thin film. Its characteristics are: The preparation method comprises the following steps performed in sequence: (1) First, dissolve Na2WO4·2H2O and NH4VO3 in deionized water and stir magnetically for 15 min at room temperature. Then, add hydrochloric acid to the above solution and stir magnetically for 20 min until no more yellow precipitate is formed. Mix ammonium oxalate into the above suspension. Stir until the solution becomes clear to obtain the precursor solution. (2) Place the cleaned and prepared FTO substrate with the conductive side facing down in the inner liner of the high-pressure reactor and carry out hydrothermal synthesis at a certain temperature. After the high-pressure reactor cools to room temperature, take out the FTO substrate, rinse it several times with deionized water, and dry it in an oven at 60°C. (3) Using aqueous solutions of CuCl2 and ZnCl2 as precursor solutions, the mixture was magnetically stirred for 20 min at room temperature. (4) The obtained V-doped WO3 / FTO was tilted at a certain angle (45°) onto the inner wall beforehand. The solution was then transferred to a 25 ml stainless steel autoclave lined with polytetrafluoroethylene. The autoclave was then sealed and heated at a certain temperature. After the autoclave cooled naturally to room temperature, the obtained sample was slowly and carefully washed several times with alcohol and distilled water and dried in an oven at 60°C. (5) Place the FTO prepared in step (4) in a box-type resistance furnace for heat treatment, and take it out after cooling to room temperature.
2. The method for preparing a Zn&V dual-doped CuWO4 photoelectrocatalytic thin film as described in claim 1, characterized in that, The process parameters for step (1) are as follows: Dissolve 0.1g–0.4g Na₂WO₄ and 0.01g–0.04g NH₄VO₃ in 30ml–60ml of deionized water, with an NH₄VO₃ incorporation ratio of 2%–10%. Stir magnetically at room temperature for 15min, then add 6ml–12ml HCl (3M) to adjust the pH of the solution, and continue stirring for 20min until no more yellow precipitate forms. Then add 0.2g–0.5g ammonium oxalate and stir the solution until clear to obtain the precursor solution.
3. The method for preparing a Zn&V dual-doped CuWO4 photoelectrocatalytic thin film as described in claim 1, characterized in that, The process parameters for step (2) are as follows: place the cleaned and prepared FTO with the conductive side facing down in the inner liner of the high-pressure reactor, pour in the precursor solution prepared in step (1), perform hydrothermal reaction at 160℃~200℃ for 6h~10h, cool to room temperature, remove the FTO and wash it with deionized water, and dry it at 60℃ to obtain a V-doped WO3 film.
4. The method for preparing a Zn&V dual-doped CuWO4 photoelectrocatalytic thin film as described in claim 1, characterized in that, The process parameters for step (3) are as follows: 0.1g to 0.4g CuCl2 and 0.01g to 0.04g ZnCl2 are dissolved in deionized water, and the ZnCl2 doping ratio is 2% to 10%. The precursor solution is prepared by magnetic stirring at room temperature.
5. The method for preparing a Zn&V dual-doped CuWO4 photoelectrocatalytic thin film as described in claim 1, characterized in that, The process parameters for step (4) are as follows: the V-doped WO3 / FTO obtained in advance is placed with the conductive side facing down in the inner liner of the high-pressure reactor, the precursor liquid prepared in step (3) is poured in, and a hydrothermal reaction is carried out at 170℃~190℃ for 8h~12h. After cooling to room temperature, the FTO is taken out and washed with deionized water, and then dried in an oven.
6. The method for preparing a Zn&V dual-doped CuWO4 photoelectrocatalytic thin film as described in claim 1, characterized in that, The process parameters for step (5) are as follows: the FTO prepared in step (4) is placed in a box-type resistance furnace for heat treatment, calcined at 450℃~550℃ for 1h~3h, and then cooled to room temperature before being taken out to prepare a Zn&V double-doped CuWO4 photoelectrocatalytic thin film.