Preparation method of BiVO4 film material for photoelectrocatalysis
BiVO4 thin films were prepared by solvothermal and hydrothermal methods, which solved the problem of low photocurrent density in photoelectrocatalysis of BiVO4 thin film materials. This method broadened the light absorption range and effectively separated photogenerated electron-hole pairs, thereby improving photoelectrocatalytic performance while maintaining the characteristics of low cost and ease of operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TIANJIN CHENGJIAN UNIV
- Filing Date
- 2024-10-14
- Publication Date
- 2026-04-14
AI Technical Summary
Existing BiVO4 thin film materials suffer from low carrier mobility, severe internal surface charge recombination, and high kinetic barriers in photoelectrocatalysis, resulting in photocurrent densities lower than theoretical values, posing a challenge to the preparation of highly photoelectrocatalytically active thin films.
BiOBr precursor solution was prepared by solvothermal method, followed by growth of BiOBr film on FTO glass, and then converted into BiVO4 film by hydrothermal method. The specific steps include magnetic stirring, solvothermal reaction and washing and drying treatment. The temperature and time of each step were controlled to optimize the film performance.
It broadens the light absorption range, promotes the separation of photogenerated electron-hole pairs, improves the photoelectrocatalytic performance of BiVO4 thin films, and the preparation method is simple, easy to operate, and low in cost.
Smart Images
Figure HSA0000299756270000011 
Figure HSA0000299756270000012
Abstract
Description
Technical Field
[0001] This invention belongs to the field of photoelectrocatalytic thin film material preparation technology, specifically a method for preparing BiVO4 composite thin film material for photoelectrocatalysis. Background Technology
[0002] With the rapid development of science and technology and society, the demand for coal, oil, natural gas, and other mineral energy sources is constantly increasing. However, in the short term, humanity will still be unable to break free from its dependence on these minerals and energy sources. Since mineral energy is a non-renewable resource, long-term, large-scale use will lead to global environmental pollution, continuously increasing energy consumption, and a global energy shortage. Therefore, developing and utilizing new energy sources has become an urgent issue for human development. Scientists have begun to focus on new renewable energy sources such as solar energy, biomass and geothermal energy, and hydrogen energy. Among these, hydrogen energy, as a green energy source, is widely used in various green energy fields due to its high energy density, environmental friendliness, and lack of secondary pollution. Currently, China has a certain foundation in the hydrogen energy industry, with an annual hydrogen production capacity of over 20 million tons. However, domestic hydrogen production currently relies mainly on fossil fuels, and the scope of hydrogen production technology promotion and the scale of hydrogen energy utilization are relatively small.
[0003] To improve this situation, scientists have developed many new methods for producing hydrogen, such as bio-enzymatic hydrogen production, electrochemical hydrogen production, and thermochemical hydrogen production. However, high production costs, low hydrogen production efficiency, and difficulty in recycling limit the practical application of these technologies. Besides hydrogen energy, solar energy is also a pollution-free, clean, and reliable energy source. Its radiation range is not limited to any one region. According to data, its radiation intensity is approximately equivalent to the heat generated by burning 300 million tons of coal in the same amount of time, approximately 8.79 × 10⁻⁶ tons. 12 kJ. To better utilize solar energy, researchers have developed many new technologies, such as solar cells and water heaters. However, due to low energy flux density, unstable radiation, and difficulty in collection, large amounts of collection and conversion devices are required. Furthermore, the storage and transportation of solar energy are challenging, thus significantly limiting the large-scale industrial application of solar energy. If solar energy can be effectively collected and rationally utilized, it will provide humanity with unlimited energy resources. Photoelectrocatalytic water splitting for hydrogen production offers an economical and environmentally friendly approach.
[0004] Photoelectrochemical "artificial green leaves" technology simulates plant photosynthesis, utilizing solar energy to decompose water and produce high-calorific-value, low-energy-consumption, and zero-pollution clean fuel (green hydrogen), attracting widespread attention in the field of renewable energy conversion. Semiconductor light absorbers, acting as the "green leaves" in artificial photosynthesis, play a crucial role in key steps such as absorbing sunlight, separating and transferring photogenerated carriers, and promoting surface redox reactions. The band structure of a semiconductor is its most fundamental property, directly affecting the performance of PEC water oxidation. The band gap should be sufficiently small to ensure absorption of a wide range of wavelengths of sunlight, while the band positions should be conducive to both water oxidation and reduction, thereby lowering the photocurrent initiation potential.
[0005] BiVO4 is considered an excellent photoanode due to its advantages such as low cost, good chemical stability, strong visible light activity, and narrow bandgap (2.4 eV). However, the low carrier mobility, severe internal surface charge recombination, and high kinetic barrier of unmodified BiVO4 result in a photocurrent density significantly lower than the theoretical value of 7.50 mA / cm². 2 (AM 1.5G, 100mW / cm) 2 Therefore, the preparation of highly photocatalytically active BiVO4 thin films remains a significant challenge. Summary of the Invention
[0006] To address the aforementioned problems of BiVO4 thin film materials in photoelectrocatalysis, the present invention aims to provide a method for preparing photoelectrocatalytic composite thin film materials that is simple to operate and has low overall cost.
[0007] To achieve the above objectives, the present invention provides a method for preparing a photoelectrocatalyzed BiVO4 thin film material comprising the following steps performed in sequence:
[0008] (1) Dissolve bismuth nitrate pentahydrate in ethylene glycol and stir magnetically for a certain time at room temperature, then label it as solution A; dissolve hexadecyltrimethylammonium bromide in ethanol and stir magnetically for a certain time at room temperature, then label it as solution B; slowly add solution B to solution A and stir magnetically for a certain time at room temperature to obtain a precursor solution; transfer the precursor solution to a reaction vessel containing FTO glass and perform a solvothermal reaction at a certain temperature for a certain time; wash and dry the FTO glass to obtain BiOBr thin film material.
[0009] (2) Ammonium metavanadate was dissolved in deionized water and stirred magnetically at room temperature for a certain time. The solution was then transferred into a reaction vessel containing BiOBr grown with FTO glass. After a certain time of solvothermal reaction at a certain temperature, the FTO glass was washed and dried to obtain BiVO4 thin film material.
[0010] In step (1), the concentration of bismuth nitrate pentahydrate is 10-12 mM, the concentration of hexadecyltrimethylammonium bromide is 8-10 mM, the magnetic stirring temperature and stirring time are 20-25℃ and 0.5-1 h, respectively, and the solvothermal temperature and time are 160-180℃ and 2-4 h, respectively.
[0011] In step (2), the concentration of ammonium metavanadate is 2-3 mol / L, the magnetic stirring temperature and stirring time are 20-25℃ and 0.5-1h, respectively, and the hydrothermal temperature and time are 160-180℃ and 22-24h, respectively.
[0012] The method for preparing BiVO4 thin film material for photoelectrocatalysis provided by this invention has the following beneficial effects:
[0013] (1) The present invention can effectively broaden the light absorption range and promote the separation of photogenerated electron-hole pairs.
[0014] (2) The preparation method of the present invention is simple and easy to operate, and the overall cost is low.
[0015] (3) The BiVO4 thin film material prepared by the present invention has excellent photoelectrocatalytic performance. Attached Figure Description
[0016] Figure 1 This is a flowchart of the preparation process for BiVO4 thin film materials.
[0017] Figure 2 The image shows a linear scanning voltammetry diagram of the BiVO4 thin film material obtained in the examples. Detailed Implementation
[0018] 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.
[0019] Example 1
[0020] A method for preparing BiVO4 thin film material for photoelectrocatalysis includes the following steps:
[0021] (1) Add 0.48g of bismuth nitrate pentahydrate to 30ml of ethylene glycol and stir magnetically at room temperature for 1h, labeling it solution A. Add 0.37g of hexadecyltrimethylammonium bromide to 40ml of anhydrous ethanol and stir magnetically at room temperature for 1h, labeling it solution B. After stirring magnetically at room temperature for 1h, solution B is slowly added dropwise to solution A, and the mixture is stirred magnetically at room temperature for 1h to obtain the precursor solution. Divide the precursor solution into equal portions and place them into a 25ml hydrothermal reactor containing FTO glass. Maintain the temperature at 160°C for 3h. After washing and drying, BiOBr thin film material is obtained.
[0022] (2) Add 0.14g of ammonium metavanadate to 60ml of deionized water, stir magnetically for 0.5h at room temperature, divide into 25ml of reaction vessel containing FTO glass for BiOBr growth, hydrothermally heat at 180° for 22h, remove and wash with deionized water several times, and dry at 60° to obtain BiVO4 thin film material.
[0023] Example 2
[0024] A method for preparing BiVO4 thin film material for photoelectrocatalysis includes the following steps:
[0025] (1) Add 0.52g of bismuth nitrate pentahydrate to 30ml of ethylene glycol and stir magnetically at room temperature for 0.5h, labeling this solution A. Add 0.4g of hexadecyltrimethylammonium bromide to 40ml of anhydrous ethanol and stir magnetically at room temperature for 0.5h, labeling this solution B. After stirring magnetically at room temperature for 0.5h, slowly add solution B dropwise to solution A and stir magnetically at room temperature for 0.5h to obtain the precursor solution. Divide the precursor solution into equal portions and place them into a 25ml hydrothermal reactor containing FTO glass. Maintain the temperature at 180°C for 2h. After washing and drying, obtain the BiOBr thin film material.
[0026] (2) Add 0.16g of ammonium metavanadate to 60ml of deionized water, stir magnetically for 1h at room temperature, divide into 25ml of reaction vessel containing BiOBr grown FTO glass, hydrothermally heat at 180° for 23h, remove and wash with deionized water several times, and dry at 60° to obtain BiVO4 thin film material.
[0027] Example 3
[0028] A method for preparing BiVO4 thin film material for photoelectrocatalysis includes the following steps:
[0029] (1) Add 0.48g of bismuth nitrate pentahydrate to 30ml of ethylene glycol and stir magnetically at room temperature for 0.5h, labeling this solution A. Add 0.37g of hexadecyltrimethylammonium bromide to 40ml of anhydrous ethanol and stir magnetically at room temperature for 0.5h, labeling this solution B. After stirring magnetically at room temperature for 0.5h, slowly add solution B dropwise to solution A and stir magnetically at room temperature for 0.5h to obtain the precursor solution. Divide the precursor solution into equal portions and place them into a 25ml hydrothermal reactor containing FTO glass. Maintain the temperature at 180°C for 2h. After washing and drying, obtain the BiOBr thin film material.
[0030] (2) Add 0.21g of ammonium metavanadate to 90ml of deionized water, stir magnetically for 0.7h at room temperature, divide into 25ml of reaction vessel containing FTO glass for BiOBr growth, hydrothermally heat at 160° for 24h, remove and wash with deionized water several times, and dry at 60° to obtain BiVO4 thin film material.
[0031] 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, descriptions of some components and 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 BiVO4 thin film material for photoelectrocatalysis, characterized in that: The preparation method comprises the following steps performed in sequence: (1) Dissolve bismuth nitrate pentahydrate in ethylene glycol and stir magnetically for a certain time at room temperature, then label it as solution A; dissolve hexadecyltrimethylammonium bromide in ethanol and stir magnetically for a certain time at room temperature, then label it as solution B; slowly add solution B to solution A and stir magnetically for a certain time at room temperature to obtain a precursor solution; transfer the precursor solution to a reaction vessel containing FTO glass and perform a solvothermal reaction at a certain temperature for a certain time; wash and dry the FTO glass to obtain BiOBr thin film material. (2) Ammonium metavanadate was dissolved in deionized water and stirred magnetically at room temperature for a certain time. The solution was then transferred to a reaction vessel containing FTO glass for BiOBr growth. After a certain time of solvothermal reaction at a certain temperature, the FTO glass was washed and dried to obtain BiVO4 thin film material.
2. The method for preparing BiVO4 thin film material for photoelectrocatalysis according to claim 1, characterized in that: In step (1), the concentration of bismuth nitrate pentahydrate is 10-12 mM, the concentration of hexadecyltrimethylammonium bromide is 8-10 mM, the magnetic stirring temperature and stirring time are 20-25℃ and 0.5-1 h, respectively, and the solvothermal temperature and time are 160-180℃ and 2-4 h, respectively.
3. The method for preparing BiVO4 thin film material for photoelectrocatalysis according to claim 1, characterized in that: In step (2), the concentration of ammonium metavanadate is 2-3 mol / L, the magnetic stirring temperature and stirring time are 20-25℃ and 0.5-1h, respectively, and the hydrothermal temperature and time are 160-180℃ and 22-24h, respectively.