Preparation method and application of Bi2MoO6 / CdS composite photoelectrocatalyst
Patent Information
- Application Number
- CN202610839465.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-11
- Publication Date
- 2026-09-18
AI Technical Summary
但纯相钼酸铋存在光生载流子复合速率高、量子效率偏低、可见光捕获能力不足等缺点，极大制约了其实际应用，仍需通过改性策略优化催化性能
本发明通过两步水热法合成Bi2MoO6/CdS复合光电催化剂，制备工艺简单、条件温和、操作性强；本发明可通过调节前驱体比例、反应温度与时间等，获得物相纯正、结构稳定的Bi2MoO6基体，保障复合体系整体性能；本发明利用水热复合实现CdS与Bi2MoO6复合，形成清晰的异质结形貌，可灵活调控材料形貌与组分分布；本发明制备的Bi2MoO6/CdS复合材料可显著提升光吸收能力、载流子分离效率与表面催化活性，在碱性电解液中表现出优异的光电催化析氧性能。
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of photoelectrocatalysis technology, specifically relating to a Bi2MoO6 / CdS composite photoelectrocatalyst, its preparation method, and its application. Background Technology
[0002] The global energy shortage and ecological pollution situation is becoming increasingly severe. The massive consumption of fossil fuels has exacerbated resource scarcity and environmental damage. Developing green and efficient energy conversion and environmental governance technologies has become a key focus of cutting-edge scientific research. Photoelectrocatalysis, relying on solar energy to drive reactions such as hydrogen production from water, pollutant degradation, and carbon dioxide reduction, combines energy conversion and environmental governance efficiency, making it an ideal path to solve energy and environmental problems. Semiconductor materials are the core of photoelectrocatalysis systems; their light-harvesting ability, carrier separation efficiency, catalytic activity, and structural stability directly affect catalytic performance. Therefore, constructing high-performance semiconductor photoelectrocatalytic materials has become a core research direction in this field.
[0003] Among various semiconductor photoelectrocatalytic materials, bismuth-based oxides have become a research hotspot due to their unique layered crystal structure, suitable band gap, and excellent chemical stability. Bismuth molybdate, as a typical Olivieris-type layered oxide, has a band gap between 2.5 and 2.8 eV, enabling visible light response and exhibiting higher solar energy utilization efficiency compared to titanium dioxide. Furthermore, Bi₂MoO₆ possesses advantages such as low toxicity, readily available raw materials, and good stability, showing significant potential for application in photoelectrocatalysis fields such as pollutant degradation and photocatalytic water splitting for hydrogen production. However, pure-phase bismuth molybdate suffers from drawbacks such as high photogenerated carrier recombination rate, low quantum efficiency, and insufficient visible light capture ability, which greatly restricts its practical application. Therefore, modification strategies are still needed to optimize its catalytic performance.
[0004] Cadmium sulfide (CdS) is a typical narrow bandgap semiconductor with a bandgap of approximately 2.4 eV. It exhibits a wide visible light response range, high electron mobility, and a well-suited band structure, enabling efficient utilization of visible light and conduction of photogenerated carriers. It is commonly used to modify wide bandgap semiconductors. Constructing heterojunctions by combining CdS with Bi₂MoO₆ can effectively improve the inherent defects of single-phase materials. This composite system utilizes energy level matching to create a built-in electric field, accelerating the separation and migration of photogenerated carriers, suppressing electron-hole recombination, and improving quantum efficiency. Simultaneously, it broadens the visible light response range, improves light energy utilization, enriches surface catalytic active sites, optimizes reaction kinetics, and achieves a synergistic improvement in photoelectrocatalytic performance. Compared to single-matrix materials, the Bi₂MoO₆ / CdS heterojunction demonstrates superior overall performance, providing an effective research approach for preparing highly efficient visible light-driven photoelectrocatalytic materials. Summary of the Invention
[0005] The purpose of this invention is to provide a method for preparing and applying a Bi2MoO6 / CdS composite photocatalyst. This invention uses a solvothermal method to synthesize the composite photocatalyst. The prepared Bi2MoO6 / CdS composite photocatalyst has highly efficient photocatalytic properties and can efficiently produce oxygen as a photoanode.
[0006] To achieve the above objectives, the preparation method of the present invention includes the following steps: The technical solution adopted is: 1) Take bismuth nitrate pentahydrate and ammonium molybdate in a molar ratio of 1:0.5 to 2. Then dissolve bismuth nitrate pentahydrate and ammonium molybdate in ethylene glycol and deionized water, respectively, to obtain bismuth nitrate pentahydrate solution with a concentration of 51 to 103 mmol / L and ammonium molybdate solution with a concentration of 321 to 674 mmol / L. Mix the obtained solutions evenly and place them in a hydrothermal reactor. Keep them at 120℃ to 160℃ for 6 to 10 hours and then cool them to room temperature. Wash the obtained samples with water and alcohol alternately and then dry them to obtain bismuth molybdate powder. 2) Take cadmium acetate, thioacetamide and PVP in a molar ratio of 1 to 3: 1: 0.1, then dissolve cadmium acetate and thioacetamide in deionized water to obtain a mixed solution with a cadmium ion concentration of 40 to 121 mmol / L, and then add PVP dispersant to the mixed solution and stir to obtain solution A. 3) Take 0.2-0.4 g of bismuth molybdate powder and add it to 20-60 mL of solution A. After stirring for 4-12 h, place the mixed solution in a hydrothermal reactor and keep it in an oven at 120-160℃ for 4-8 h. After washing the obtained sample with water and alcohol alternately, dry it to obtain Bi2MoO6 / CdS composite photocatalyst.
[0007] The water-alcohol alternating rinse in steps 1) and 3) is to rinse with water and alcohol alternately 1 to 3 times.
[0008] The Bi2MoO6 / CdS composite photocatalyst was prepared according to the preparation method of the present invention.
[0009] The Bi2MoO6 / CdS composite photocatalyst prepared according to the method of the present invention can be used for oxygen production at the photoanode.
[0010] The preparation method of the present invention has the following beneficial effects: This invention synthesizes a Bi₂MoO₆ / CdS composite photocatalyst via a two-step hydrothermal method. The preparation process is simple, mild, and highly operable. By adjusting the precursor ratio, reaction temperature, and time, a pure and structurally stable Bi₂MoO₆ matrix can be obtained, ensuring the overall performance of the composite system. This invention utilizes hydrothermal composite technology to achieve the composite of CdS and Bi₂MoO₆, forming a clear heterojunction morphology, allowing for flexible control of material morphology and component distribution. The Bi₂MoO₆ / CdS composite material prepared by this invention significantly improves light absorption capacity, carrier separation efficiency, and surface catalytic activity, exhibiting excellent photocatalytic oxygen evolution performance in alkaline electrolytes. Attached Figure Description
[0011] Figure 1 The image shows the X-ray diffraction pattern of Bi2MoO6 / CdS prepared in Example 2, where the horizontal axis represents the 2θ angle and the vertical axis represents the diffraction peak intensity.
[0012] Figure 2 This is a scan image of the Bi2MoO6 / CdS prepared in Example 2.
[0013] Figure 3 Example 2 shows the oxygen evolution performance of Bi2MoO6 / CdS prepared in a solution with pH 9.5. Detailed Implementation Example 1: 1) Take bismuth nitrate pentahydrate and ammonium molybdate in a molar ratio of 1:0.5, then dissolve bismuth nitrate pentahydrate and ammonium molybdate in ethylene glycol and deionized water respectively to obtain a bismuth nitrate pentahydrate solution with a concentration of 51 mmol / L and an ammonium molybdate solution with a concentration of 321 mmol / L. Mix the obtained solutions evenly and place them in a hydrothermal reactor. Keep them at 120℃ for 10 h and then cool them to room temperature. Wash the obtained samples twice with water and alcohol alternately and then dry them to obtain bismuth molybdate powder. 2) Take cadmium acetate, thioacetamide and PVP in a molar ratio of 1:1:0.1, then dissolve cadmium acetate and thioacetamide in deionized water to obtain a mixed solution with a cadmium ion concentration of 40 mmol / L, and then add PVP dispersant to the mixed solution and stir to obtain solution A. 3) Take 0.2g of bismuth molybdate powder and add it to 30mL of solution A. After stirring for 4h, place the mixed solution in a hydrothermal reactor and keep it at 120℃ for 8h in an oven. After washing the obtained sample twice with water and alcohol alternately, dry it to obtain Bi2MoO6 / CdS composite photocatalyst.
[0014] Example 2: 1) Take bismuth nitrate pentahydrate and ammonium molybdate in a 1:1 molar ratio, then dissolve bismuth nitrate pentahydrate and ammonium molybdate in ethylene glycol and deionized water respectively to obtain a bismuth nitrate pentahydrate solution with a concentration of 80 mmol / L and an ammonium molybdate solution with a concentration of 450 mmol / L. After mixing the obtained solutions evenly, place them in a hydrothermal reactor, keep them at 140℃ for 8 hours, and then cool them to room temperature. Wash the obtained samples with water and alcohol alternately 3 times and then dry them to obtain bismuth molybdate powder. 2) Take cadmium acetate, thioacetamide and PVP in a molar ratio of 2:1:0.1, then dissolve cadmium acetate and thioacetamide in deionized water to obtain a mixed solution with a cadmium ion concentration of 60 mmol / L, and then add PVP dispersant to the mixed solution and stir to obtain solution A. 3) Take 0.3g of bismuth molybdate powder and add it to 20mL of solution A. After stirring for 6h, place the mixed solution in a hydrothermal reactor and keep it at 140℃ for 6h in an oven. After washing the obtained sample with water and alcohol alternately 3 times, dry it to obtain Bi2MoO6 / CdS composite photoelectrocatalyst.
[0015] Depend on Figure 1 It can be seen that the Bi2MoO6 / CdS composite photocatalyst prepared in this invention can accurately correspond to Bi2MoO6 PDF#76-2388 and CdS PDF#41-1049, indicating that the Bi2MoO6 / CdS composite catalyst was successfully prepared.
[0016] Depend on Figure 2 It can be seen that the prepared Bi2MoO6 / CdS composite photoelectrocatalyst clearly exhibits both sheet-like and rod-like structures, and combines the morphological characteristics of Bi2MoO6 and CdS, proving that it is a composite.
[0017] The photoelectrocatalytic effect of the prepared Bi₂MoO₆ / CdS was tested using a Chi660E instrument. The specific testing procedure included weighing 10 mg of the composite photoelectrocatalyst, adding 80 μL of isopropanol and 5 μL of naphthol, sonicating for 30 min, transferring 5 μL of the reagent to the test electrode, drying it, and then placing it in a sodium tetraborate solution at pH 9.5 for photoelectrochemical oxygen evolution testing. It can be clearly seen that the photoelectrocatalyst prepared in this invention achieves a photocurrent density of 0.312 mA / cm² at 1.23 V. 2, It exhibits good photoelectrocatalytic oxygen production performance.
[0018] Example 3: 1) Take bismuth nitrate pentahydrate and ammonium molybdate in a molar ratio of 1:1.5, then dissolve bismuth nitrate pentahydrate and ammonium molybdate in ethylene glycol and deionized water respectively to obtain a bismuth nitrate pentahydrate solution with a concentration of 103 mmol / L and an ammonium molybdate solution with a concentration of 674 mmol / L. After mixing the obtained solutions evenly, place them in a hydrothermal reactor, keep them at 130℃ for 9 hours, and then cool them to room temperature. Wash the obtained samples with water and alcohol alternately once and then dry them to obtain bismuth molybdate powder. 2) Take cadmium acetate, thioacetamide and PVP in a molar ratio of 3:1:0.1, then dissolve cadmium acetate and thioacetamide in deionized water to obtain a mixed solution with a cadmium ion concentration of 80 mmol / L, and then add PVP dispersant to the mixed solution and stir to obtain solution A. 3) Take 0.4g of bismuth molybdate powder and add it to 50mL of solution A. After stirring for 10h, place the mixed solution in a hydrothermal reactor and keep it at 150℃ for 7h in an oven. After washing the obtained sample with water and alcohol alternately once, dry it to obtain Bi2MoO6 / CdS composite photocatalyst.
[0019] Example 4: 1) Take bismuth nitrate pentahydrate and ammonium molybdate in a molar ratio of 1:0.8, then dissolve bismuth nitrate pentahydrate and ammonium molybdate in ethylene glycol and deionized water respectively to obtain a bismuth nitrate pentahydrate solution with a concentration of 60 mmol / L and an ammonium molybdate solution with a concentration of 400 mmol / L. After mixing the obtained solutions evenly, place them in a hydrothermal reactor, keep them at 160℃ for 6 hours, and then cool them to room temperature. Wash the obtained samples with water and alcohol alternately 3 times and then dry them to obtain bismuth molybdate powder. 2) Take cadmium acetate, thioacetamide and PVP in a molar ratio of 1.5:1:0.1, then dissolve cadmium acetate and thioacetamide in deionized water to obtain a mixed solution with a cadmium ion concentration of 100 mmol / L, and then add PVP dispersant to the mixed solution and stir to obtain solution A. 3) Take 0.25g of bismuth molybdate powder and add it to 40mL of solution A. After stirring for 8h, place the mixed solution in a hydrothermal reactor and keep it at 130℃ for 4h in an oven. After washing the obtained sample with water and alcohol alternately 3 times, dry it to obtain Bi2MoO6 / CdS composite photocatalyst.
[0020] Example 5: 1) Take bismuth nitrate pentahydrate and ammonium molybdate in a molar ratio of 1:1.2, then dissolve bismuth nitrate pentahydrate and ammonium molybdate in ethylene glycol and deionized water respectively to obtain a bismuth nitrate pentahydrate solution with a concentration of 90 mmol / L and an ammonium molybdate solution with a concentration of 600 mmol / L. After mixing the obtained solutions evenly, place them in a hydrothermal reactor, keep them at 150℃ for 7 h, and then cool them to room temperature. Wash the obtained samples twice with water and alcohol alternately and then dry them to obtain bismuth molybdate powder. 2) Take cadmium acetate, thioacetamide and PVP in a molar ratio of 2.5:1:0.1, then dissolve cadmium acetate and thioacetamide in deionized water to obtain a mixed solution with a cadmium ion concentration of 121 mmol / L, and then add PVP dispersant to the mixed solution and stir to obtain solution A. 3) Take 0.35g of bismuth molybdate powder and add it to 60mL of solution A. After stirring for 8h, place the mixed solution in a hydrothermal reactor and keep it at 160℃ for 5h in an oven. After washing the obtained sample with water and alcohol alternately 3 times, dry it to obtain Bi2MoO6 / CdS composite photoelectrocatalyst.
[0021] Example 6: 1) Take bismuth nitrate pentahydrate and ammonium molybdate in a molar ratio of 1:2, then dissolve bismuth nitrate pentahydrate and ammonium molybdate in ethylene glycol and deionized water respectively to obtain a bismuth nitrate pentahydrate solution with a concentration of 70 mmol / L and an ammonium molybdate solution with a concentration of 500 mmol / L. After mixing the obtained solutions evenly, place them in a hydrothermal reactor, keep them at 135℃ for 9 hours, and then cool them to room temperature. Wash the obtained samples with water and alcohol alternately 3 times and then dry them to obtain bismuth molybdate powder. 2) Take cadmium acetate, thioacetamide and PVP in a molar ratio of 2:1:0.1, then dissolve cadmium acetate and thioacetamide in deionized water to obtain a mixed solution with a cadmium ion concentration of 90 mmol / L, and then add PVP dispersant to the mixed solution and stir to obtain solution A. 3) Take 0.4g of bismuth molybdate powder and add it to 50mL of solution A. After stirring for 5h, place the mixed solution in a hydrothermal reactor and keep it at 145℃ for 7h in an oven. After washing the obtained sample twice with water and alcohol alternately, dry it to obtain Bi2MoO6 / CdS composite photocatalyst.
[0022] Example 7: 1) Take bismuth nitrate pentahydrate and ammonium molybdate in a molar ratio of 1:1.8, then dissolve bismuth nitrate pentahydrate and ammonium molybdate in ethylene glycol and deionized water respectively to obtain a bismuth nitrate pentahydrate solution with a concentration of 100 mmol / L and an ammonium molybdate solution with a concentration of 550 mmol / L. After mixing the obtained solutions evenly, place them in a hydrothermal reactor, keep them at 155℃ for 7 h, and then cool them to room temperature. Wash the obtained samples with water and alcohol alternately once and then dry them to obtain bismuth molybdate powder. 2) Take cadmium acetate, thioacetamide and PVP in a molar ratio of 3:1:0.1, then dissolve cadmium acetate and thioacetamide in deionized water to obtain a mixed solution with a cadmium ion concentration of 70 mmol / L, and then add PVP dispersant to the mixed solution and stir to obtain solution A. 3) Take 0.2g of bismuth molybdate powder and add it to 30mL of solution A. After stirring for 9h, place the mixed solution in a hydrothermal reactor and keep it at 135℃ for 5h in an oven. After washing the obtained sample with water and alcohol alternately 3 times, dry it to obtain Bi2MoO6 / CdS composite photocatalyst.
Claims
1. A method for preparing a Bi₂MoO₆ / CdS composite photocatalyst, characterized in that... Includes the following steps: 1) Take bismuth nitrate pentahydrate and ammonium molybdate in a molar ratio of 1:0.5 to 2. Then dissolve bismuth nitrate pentahydrate and ammonium molybdate in ethylene glycol and deionized water, respectively, to obtain bismuth nitrate pentahydrate solution with a concentration of 51 to 103 mmol / L and ammonium molybdate solution with a concentration of 321 to 674 mmol / L. Mix the obtained solutions evenly and place them in a hydrothermal reactor. Keep them at 120℃ to 160℃ for 6 to 10 hours and then cool them to room temperature. Wash the obtained samples with water and alcohol alternately and then dry them to obtain bismuth molybdate powder. 2) Take cadmium acetate, thioacetamide and PVP in a molar ratio of 1 to 3: 1: 0.1, then dissolve cadmium acetate and thioacetamide in deionized water to obtain a mixed solution with a cadmium ion concentration of 40 to 121 mmol / L, and then add PVP dispersant to the mixed solution and stir to obtain solution A. 3) Take 0.2-0.4 g of bismuth molybdate powder and add it to 20-60 mL of solution A. After stirring for 4-12 h, place the mixed solution in a hydrothermal reactor and keep it in an oven at 120-160℃ for 4-8 h. After washing the obtained sample with water and alcohol alternately, dry it to obtain Bi2MoO6 / CdS composite photocatalyst.
2. The preparation method of the Bi₂MoO₆ / CdS composite photocatalyst according to claim 1, characterized in that, The water-alcohol alternating rinse in steps 1) and 3) is to rinse with water and alcohol alternately 1 to 3 times.
3. A Bi2MoO6 / CdS composite photocatalyst prepared by the preparation method described in claim 1 or 2.
4. The application of a Bi2MoO6 / CdS composite photocatalyst prepared by the method described in claim 1 or 2 as a photoanode for oxygen production.