Preparation method of CdS / Co9S8-based visible-light-driven photocatalyst capable of decomposing water to produce hydrogen and oxidizing benzyl alcohol to prepare benzaldehyde
By preparing a CdS/Co9S8 catalyst, the problems of low efficiency in photocatalytic hydrolysis and environmental pollution in benzaldehyde synthesis were solved. This enabled efficient catalytic water splitting for hydrogen production and benzaldehyde production by oxidation of benzyl alcohol under visible light, simplifying the preparation process and reducing costs.
Patent Information
- Application Number
- CN202511400979.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-28
- Publication Date
- 2026-01-27
AI Technical Summary
Existing photocatalytic hydrolysis methods suffer from high thermodynamic energy barriers, slow kinetic processes, wasted photogenerated hole oxidation capacity, and high toxicity of traditional sacrificial agents. Furthermore, the synthesis of benzaldehyde requires high-valence metal salts and organic solvents, resulting in severe environmental pollution.
A CdS/Co9S8 composite material was used as a visible light catalyst. By preparing Co9S8 and adding Cd and S sources, a CdS/Co9S8 catalyst was formed, which was used to catalyze the hydrolysis of water to produce hydrogen and the oxidation of benzyl alcohol to produce benzaldehyde under visible light.
This method enables efficient catalytic water splitting for hydrogen production and benzaldehyde preparation via benzyl alcohol oxidation under visible light, simplifying the preparation process, reducing costs, and making it suitable for widespread application.
Smart Images
Figure CN121402103A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrocatalysis technology, and in particular to a method for preparing a visible light catalyst based on CdS / Co9S8 that can both decompose water to produce hydrogen and oxidize benzyl alcohol to prepare benzaldehyde. Background Technology
[0002] In today's world, energy shortages and environmental pollution are becoming increasingly severe problems, and a sustainable and environmentally friendly energy supply has become a critical issue that urgently needs to be addressed globally. Solar energy, as a clean and renewable energy source, offers a promising solution for addressing environmental degradation and the energy crisis through its conversion into chemical energy. Since Fujishima and Honda discovered in 1972 that water splitting could be achieved using titanium dioxide electrodes under ultraviolet light, photocatalytic hydrogen production has attracted widespread attention from researchers. However, as research has progressed, it has been found that photocatalytic water splitting has many inherent drawbacks, such as a large thermodynamic energy barrier and a slow kinetic process, which severely reduces photocatalytic activity. Simultaneously, the oxygen byproduct produced by water splitting has limited applications, which also restricts the development of this technology to some extent. To address these issues, hole sacrificial agents are typically added to consume photogenerated holes, promote charge separation, and enhance catalytic activity. However, most traditional sacrificial agents are toxic, not only increasing the cost of hydrogen production but also causing environmental pollution. More importantly, they waste the oxidation capacity of photogenerated holes.
[0003] On the other hand, benzaldehyde, as an important organic chemical raw material, has wide applications in fragrances, pharmaceuticals, and pesticides. Traditional industrial synthesis often employs the direct oxidation of toluene, a method that requires high-valence metal salts such as potassium permanganate and potassium dichromate as oxidants, and also necessitates large amounts of organic solvents, contradicting the principles of green and sustainable development. Therefore, developing an efficient and green method for benzaldehyde synthesis is urgently needed. If benzyl alcohol is used instead of the sacrificial agent in photocatalytic water splitting, not only can photogenerated holes be consumed, promoting photogenerated carrier separation and improving photocatalytic efficiency, but benzyl alcohol can also be oxidized to benzaldehyde, achieving coupling between photocatalytic water splitting for hydrogen production and the oxidation of benzyl alcohol to produce benzaldehyde.
[0004] Based on the above technical background, this invention develops a visible light photocatalyst preparation method based on CdS / Co9S8 that can both decompose water to produce hydrogen and oxidize benzyl alcohol to prepare benzaldehyde. No related technologies have been reported. Summary of the Invention
[0005] The purpose of this invention is to solve the technical problems existing in the prior art and to provide a method for preparing a visible light catalyst based on CdS / Co9S8 that can both decompose water to produce hydrogen and oxidize benzyl alcohol to prepare benzaldehyde.
[0006] To achieve the above objectives, the technical solution provided by this invention is: a method for preparing a visible light photocatalyst based on CdS / Co9S8 that can both decompose water to produce hydrogen and oxidize benzyl alcohol to prepare benzaldehyde, characterized in that: the preparation method first prepares Co9S8, and then further converts Co9S8 into CdS / Co9S8 by adding a Cd source and an S source, thereby obtaining a visible light photocatalyst based on CdS / Co9S8; specifically including the following steps:
[0007] Step (1): Preparation of Co9S8
[0008] 0.787 g of cobalt sulfate heptahydrate and 0.639 g of thiourea (8.40 mmol) were dissolved in 14 mL of ethylene glycol and 56 mL of DMF to obtain mixed solution A. Mixed solution A was stirred continuously at room temperature for 30 minutes and then transferred to a 100 mL autoclave. Mixed solution A in the autoclave was heated at 160 °C for 12 hours and then cooled to room temperature to obtain powder. The powder was filtered and washed with deionized water and ethanol. After vacuum drying at 60 °C for 6 hours, Co9S8 was obtained.
[0009] Step (2): Preparation of CdS / Co9S8 composite material
[0010] 206 mg Cd(CH3COO)2·2H2O, 375 mg thioacetamide, and a certain amount of Co9S8 obtained in step (1) were added to 50 mL of deionized water to obtain a homogeneous mixed solution B. The homogeneous mixed solution B was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and stirred for 30 minutes. Then, a hydrothermal reaction was carried out at a certain temperature for 12 hours to obtain the reaction product. After the reaction was completed, the reaction product was centrifuged to separate the precipitate, washed with ethanol and deionized water, and dried to obtain the CdS / Co9S8 composite material.
[0011] Preferably, the amount of Co9S8 added in step (2) is in the range of 10-40 mg.
[0012] Preferably, the hydrothermal reaction temperature in step (2) is in the range of 120-220℃.
[0013] Beneficial effects of this invention:
[0014] 1. The CdS / Co9S8 catalyst prepared in this invention can efficiently catalyze the hydrolysis of water to produce hydrogen and the oxidation of benzyl alcohol to produce benzaldehyde under visible light.
[0015] 2. The CdS / Co9S8 catalyst prepared by this invention is simple to prepare, low in cost, and suitable for large-scale application. Attached Figure Description
[0016] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.
[0017] Figure 1 Transmission electron microscopy image of the CdS / Co9S8 catalyst prepared in Specific Example 2 of this invention;
[0018] Figure 2 The graph shows the performance of the CdS / Co9S8 catalyst prepared in Specific Example 2 of this invention in catalyzing water splitting to produce hydrogen and oxidizing benzyl alcohol to produce benzaldehyde under visible light. Detailed Implementation
[0019] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention. Specific Implementation Example 1
[0021] Step (1): Preparation of Co9S8
[0022] 0.787 g of 2.80 mmol cobalt sulfate heptahydrate and 0.639 g of 8.40 mmol thiourea were dissolved in 14 mL of ethylene glycol and 56 mL of DMF to obtain mixed solution A. Mixed solution A was stirred continuously at room temperature for 30 minutes, then transferred to a 100 mL autoclave. Mixed solution A in the autoclave was heated at 160 °C for 12 hours and cooled to room temperature to obtain a powder. The powder was filtered and washed with deionized water and ethanol. Co9S8 was obtained after vacuum drying at 60 °C for 6 hours.
[0023] Step (2): Preparation of CdS / Co9S8 composite material
[0024] 206 mg Cd(CH3COO)2·2H2O, 375 mg thioacetamide, and 10.3 mg Co9S8 obtained in step (1) were added to 50 mL of deionized water to obtain a homogeneous mixed solution B. The homogeneous mixed solution B was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and stirred for 30 minutes. Then, a hydrothermal reaction was carried out at 120 °C for 12 hours to obtain the reaction product. After the reaction was completed, the reaction product was centrifuged to separate the precipitate, washed with ethanol and deionized water, and dried to obtain the CdS / Co9S8 composite material. Specific Implementation Example 2
[0026] Step (1): Preparation of Co9S8
[0027] 0.787 g of 2.80 mmol cobalt sulfate heptahydrate and 0.639 g of 8.40 mmol thiourea were dissolved in 14 mL of ethylene glycol and 56 mL of DMF to obtain mixed solution A. Mixed solution A was stirred continuously at room temperature for 30 minutes, then transferred to a 100 mL autoclave. Mixed solution A in the autoclave was heated at 160 °C for 12 hours and cooled to room temperature to obtain a powder. The powder was filtered and washed with deionized water and ethanol. Co9S8 was obtained after vacuum drying at 60 °C for 6 hours.
[0028] Step (2): Preparation of CdS / Co9S8 composite material
[0029] 206 mg Cd(CH3COO)2·2H2O, 375 mg thioacetamide, and 20.6 mg Co9S8 obtained in step (1) were added to 50 mL of deionized water to obtain a homogeneous mixed solution B. The homogeneous mixed solution B was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and stirred for 30 minutes. Then, a hydrothermal reaction was carried out at 180 °C for 12 hours to obtain the reaction product. After the reaction was completed, the reaction product was centrifuged to separate the precipitate, washed with ethanol and deionized water, and dried to obtain the CdS / Co9S8 composite material. Specific Implementation Example 3
[0031] Step (1): Preparation of Co9S8
[0032] 0.787 g of 2.80 mmol cobalt sulfate heptahydrate and 0.639 g of 8.40 mmol thiourea were dissolved in 14 mL of ethylene glycol and 56 mL of DMF to obtain mixed solution A. Mixed solution A was stirred continuously at room temperature for 30 minutes, then transferred to a 100 mL autoclave. Mixed solution A in the autoclave was heated at 160 °C for 12 hours and cooled to room temperature to obtain a powder. The powder was filtered and washed with deionized water and ethanol. Co9S8 was obtained after vacuum drying at 60 °C for 6 hours.
[0033] Step (2): Preparation of CdS / Co9S8 composite material
[0034] 206 mg Cd(CH3COO)2·2H2O, 375 mg thioacetamide, and 30.9 mg Co9S8 obtained in step (1) were added to 50 mL of deionized water to obtain a homogeneous mixed solution B. The homogeneous mixed solution B was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and stirred for 30 minutes. Then, a hydrothermal reaction was carried out at 220 °C for 12 hours to obtain the reaction product. After the reaction was completed, the reaction product was centrifuged to separate the precipitate, washed with ethanol and deionized water, and dried to obtain the CdS / Co9S8 composite material.
[0035] The CdS / Co9S8 catalyst prepared by this invention can efficiently catalyze the hydrolysis of water to produce hydrogen and the oxidation of benzyl alcohol to produce benzaldehyde under visible light. The preparation is simple, low-cost, and suitable for large-scale application.
[0036] Without causing conflict, those skilled in the art can freely combine and use the above-mentioned additional technical features.
[0037] The above description is only a preferred embodiment of the present invention. Any technical solution that achieves the purpose of the present invention by essentially the same means is within the protection scope of the present invention.
Claims
1. A method for preparing a visible light photocatalyst based on CdS / Co9S8 that can both decompose water to produce hydrogen and oxidize benzyl alcohol to prepare benzaldehyde, characterized in that: The preparation method first prepares Co9S8, and then further converts it into CdS / Co9S8 by adding Cd and S sources, thereby obtaining a visible light photocatalyst based on CdS / Co9S8; specifically, it includes the following steps: Step (1): Preparation of Co9S8 0.787 g of cobalt sulfate heptahydrate and 0.639 g of thiourea (8.40 mmol) were dissolved in 14 mL of ethylene glycol and 56 mL of DMF to obtain mixed solution A. Mixed solution A was stirred continuously at room temperature for 30 minutes and then transferred to a 100 mL autoclave. Mixed solution A in the autoclave was heated at 160 °C for 12 hours and then cooled to room temperature to obtain powder. The powder was filtered and washed with deionized water and ethanol. After vacuum drying at 60 °C for 6 hours, Co9S8 was obtained. Step (2): Preparation of CdS / Co9S8 composite material 206 mg Cd(CH3COO)2·2H2O, 375 mg thioacetamide, and a certain amount of Co9S8 obtained in step (1) were added to 50 mL of deionized water to obtain a homogeneous mixed solution B. The homogeneous mixed solution B was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and stirred for 30 minutes. Then, a hydrothermal reaction was carried out at a certain temperature for 12 hours to obtain the reaction product. After the reaction was completed, the reaction product was centrifuged to separate the precipitate, washed with ethanol and deionized water, and dried to obtain the CdS / Co9S8 composite material.
2. The method for preparing a visible light photocatalyst based on CdS / Co9S8 that can both decompose water to produce hydrogen and oxidize benzyl alcohol to prepare benzaldehyde according to claim 1, characterized in that: The amount of Co9S8 added in step (2) ranges from 10 to 40 mg.
3. The method for preparing a visible light photocatalyst based on CdS / Co9S8 that can both decompose water to produce hydrogen and oxidize benzyl alcohol to prepare benzaldehyde according to claim 1, characterized in that: The range of hydrothermal reaction temperature in step (2) is 120-220℃.