Indium zinc sulfide-based composite catalyst, preparation method thereof and application of indium zinc sulfide-based composite catalyst in photocatalytic hydrogen production

Abstract

The invention belongs to the technical field of photocatalytic nano composite materials, and particularly relates to an indium zinc sulfide-based composite catalyst, a preparation method thereof and application of the indium zinc sulfide-based composite catalyst in photocatalytic hydrogen production. The preparation method comprises the following steps: adding a mixture of a zinc source, an indium source and a sulfur source into a beaker, adding water into the beaker, and stirring to uniformly mix; carrying out hydrothermal reaction on the mixture, washing and drying to obtain a substrate catalyst; the preparation method comprises the following steps: adding a gold source into a substrate catalyst, heating to a specified temperature, adding a sodium citrate solution, preserving heat, cooling, centrifuging and washing the obtained turbid liquid, and finally drying to obtain the indium zinc sulfide based composite catalyst. The preparation method disclosed by the invention is simple to operate and has no danger; the obtained composite catalyst shows an excellent catalytic effect in a photocatalytic hydrogen production reaction. Under the irradiation of a xenon lamp, in a reaction medium aqueous solution, the hydrogen generation rate of the composite catalyst reaches 4233.5 [mu] mol / g / h.

Description

Technical Field

[0001] The invention belongs to the technical field of photocatalytic nanocomposite materials, and particularly relates to an indium zinc sulfide-based composite catalyst, a preparation method thereof, and an application thereof in photocatalytic hydrogen production. Background Art

[0002] The current global resource situation presents the following main characteristics: 1. Increasing resource shortage; 2. Uneven distribution of resources; 3. Increasing environmental pressure; 4. Insufficient utilization of circular economy and renewable resources. Overall, the global resource situation is facing the dual contradiction of shortage and growing demand. Turning to sustainable development, strengthening international cooperation and scientific and technological innovation are considered to be the key ways to deal with these challenges. Due to the existence of the above situation, people have gradually focused their research on photocatalytic reactions. Photocatalysis is of great significance in the fields of environmental protection and energy development, and can provide innovative solutions to global resource and environmental problems. Photocatalysis uses solar energy, an unlimited and clean energy, to convert it into chemical energy (such as hydrogen, fuel). Example: Photocatalytic water decomposition to produce hydrogen (H2) is regarded as an important source of clean energy in the future. Carbon dioxide conversion: Reducing CO2 to valuable chemicals (such as methanol) through photocatalysis not only alleviates greenhouse gas problems, but also provides solutions for carbon cycles. Degradation of organic pollutants: Photocatalysis can decompose organic pollutants in water or air and oxidize them into harmless substances (such as water and carbon dioxide). Example: Treatment of toxic dyes or persistent organic pollutants in industrial wastewater. Sterilization and disinfection: Photocatalytic materials (such as titanium dioxide) can generate active oxygen species under ultraviolet light, effectively killing bacteria and viruses, and are widely used in medical and water purification systems. Photocatalytic reactions often take place at room temperature and pressure, and have the advantages of high efficiency and low energy consumption. They can reduce dependence on fossil energy while reducing the carbon footprint of industrial chemical processes. Photocatalytic technology has great commercial potential and can have a profound impact in many fields such as energy, environment, agriculture and medicine. For example: photocatalytic films are used for self-cleaning glass and building materials. Photocatalytic hydrogen production technology is expected to reduce the cost of clean energy and help energy transformation. Photocatalytic research is interdisciplinary and has multiple application fields. It provides a key technical path for achieving clean energy production and environmental sustainable development, and also provides new challenges and opportunities for the scientific frontier.

[0003] Photocatalytic hydrogen production technology is an important direction for achieving clean energy development. In recent years, with the in-depth research on materials science and photocatalytic mechanisms, photocatalytic hydrogen production technology has made significant progress. ZnIn2S4 has many advantages and can be used as a photocatalytic material, such as narrow band gap, easily adjustable nanostructure, and easy growth. Therefore, it is considered to be a very promising catalyst for photocatalytic hydrogen evolution, carbon dioxide reduction, etc. However, the photocatalytic ability of pure ZnIn2S4 is lower than expected due to certain reasons such as: few active sites, slow migration of photogenerated carriers, large degree of recombination, low light conversion efficiency, etc. Therefore, in recent years, people have continuously modified indium zinc sulfide in various ways to improve its photocatalytic ability. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing an indium zinc sulfide-based composite catalytic material with excellent catalytic effect. The method is simple to implement, avoids the complicated steps of previous preparation methods, and has high operational safety.

[0005] The technical solution adopted by the present invention is: an indium zinc sulfide-based composite catalyst, the preparation method of which comprises the following steps:

[0006] 1) Add a mixture of zinc source, indium source and sulfur source into a beaker, add water thereto, and stir to mix the three evenly;

[0007] 2) Then the mixture is transferred to a reaction vessel for hydrothermal reaction, and after the hydrothermal reaction is completed, it is washed and dried to obtain a base catalyst;

[0008] 3) Adding a gold source to the base catalyst, heating to a specified temperature, then adding a sodium citrate solution and keeping the temperature for 5 to 30 minutes, cooling, centrifuging the obtained suspension, washing, and finally drying to obtain an indium zinc sulfide-based composite catalyst.

[0009] In the above-mentioned indium zinc sulfide-based composite catalyst, in step 1), the zinc source, indium source and sulfur source are respectively: zinc chloride, indium trichloride tetrahydrate and thioacetamide.

[0010] In the above-mentioned indium zinc sulfide-based composite catalyst, in step 1), the molar ratio of zinc source: indium source: sulfur source is 1:2:4.

[0011] In the above-mentioned indium zinc sulfide-based composite catalyst, in step 2), the hydrothermal reaction is carried out at 180° C. for 18 to 20 hours.

[0012] In the above-mentioned indium zinc sulfide-based composite catalyst, in step 3), the gold source is HAuCl4·xH2O.

[0013] In the above-mentioned indium zinc sulfide-based composite catalyst, in step 3), the specified temperature is 90-95°C.

[0014] In the above-mentioned indium zinc sulfide-based composite catalyst, in step 3), the mass concentration of the sodium citrate solution is 1%.

[0015] Application of the above-mentioned indium zinc sulfide-based composite catalyst in photocatalytic hydrogen production.

[0016] The above application method is as follows: a sealed reaction pool with insulation is used as a reactor, water, a specified hole sacrificial agent and a co-solvent are added to the reaction system, a xenon lamp is used as a light source, simulated sunlight is used as the radiation light, and the above indium zinc sulfide-based composite catalyst is used as a catalyst to produce hydrogen by photocatalysis.

[0017] In the above application, the hole sacrificial agent is triethanolamine and the co-solvent is acetonitrile.

[0018] The beneficial effects of the present invention are as follows: the present invention adopts a simple and safe solvent thermal method to prepare an indium zinc sulfide-based composite catalyst. The indium zinc sulfide-based composite catalyst provided by the present invention has high catalytic efficiency and good reaction effect. Under the irradiation of a xenon lamp, in a reaction medium aqueous solution, the hydrogen generation rate of the composite catalyst reaches 4233.5 μmol / g / h. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a scanning electron microscope image of the photocatalytic composite material prepared by the present invention.

[0020] Figure 2 The transmission electron microscope image of the photocatalytic composite material prepared by the present invention is

[0021] Figure 3 It is an X-ray diffraction pattern (XRD) of the photocatalytic composite material prepared by the present invention.

[0022] Figure 4 It is a solid ultraviolet absorption diagram of the photocatalytic composite material prepared by the present invention.

[0023] Figure 5 It is a photocatalytic hydrogen production performance diagram of the photocatalytic composite material prepared by the present invention. DETAILED DESCRIPTION

[0024] In order to better understand the technical solution of the present invention, a specific embodiment is given to further illustrate it, but the solution is not limited thereto.

[0025] Example 1 The preparation method of indium zinc sulfide based composite catalyst (I) is as follows:

[0026] 1mmol zinc chloride, 2mmol indium trichloride tetrahydrate and 4mmol thioacetamide were weighed and added to a glass beaker, and then 60ml deionized water was added and stirred vigorously for 30min until the three were evenly mixed. Then the hydrothermal reaction was carried out at 180℃ for 18h. After the reaction was completed, it was cooled, centrifuged, washed twice with deionized water and anhydrous ethanol, and dried overnight at 80℃ to obtain indium zinc sulfide.

[0027] Next, 0.1 g of the prepared indium zinc sulfide was added to a 100 mL two-necked flask, and 10 mL of 0.4 mmol tetrachloroauric acid aqueous solution was added and mixed. After that, it was placed in a 95°C oil bath. After reaching the specified temperature, 15 ml of 1% sodium citrate aqueous solution was added and stored for 15-20 min. Then, it was cooled, centrifuged (8000 rpm, 5 min), washed twice with water and anhydrous ethanol, and then dried overnight.

[0028] (II) Testing

[0029] 1. Figure 1 The scanning electron microscope image of the prepared indium zinc sulfide based composite catalyst is shown in Figure 2. Figure 1 It can be seen that the prepared indium zinc sulfide-based composite catalyst presents a flower-like structure as a whole, indicating that the composite catalyst has a large specific surface area, which is conducive to the reaction. In addition, no gold nanoparticles are clearly observed in the figure.

[0030] 2. Figure 2 This is a transmission electron microscope image of the prepared indium zinc sulfide based composite catalyst. Figure 2 It can be seen that there are many small black dots distributed on the edge of the prepared indium zinc sulfide-based composite catalyst, which are the loaded gold nanoparticles. This result shows that the indium zinc sulfide-based composite catalyst was successfully prepared.

[0031] 3. Table 1 is the ICP test results of the prepared indium zinc sulfide-based composite catalyst. It can be seen from Table 1 that the gold nanoparticles are indeed successfully loaded on indium zinc sulfide, which further confirms the successful synthesis of the indium zinc sulfide-based composite catalyst.

[0032] Table 1 ICP test results of indium zinc sulfide based composite catalyst

[0033]

[0034] 4. Figure 3 is the X-ray diffraction spectrum (XRD) of the prepared indium zinc sulfide based composite catalyst. Figure 3It can be seen that no other characteristic peaks were observed, which shows that the catalyst we prepared is relatively pure. However, no characteristic peaks belonging to gold were clearly observed from this. Combined with the results of transmission electron microscopy and ICP, this is because the amount of gold is too small.

[0035] 5. Figure 4 This is the solid ultraviolet absorption diagram of the prepared indium zinc sulfide-based composite catalyst. From the figure, it can be seen that after Au is loaded on indium zinc sulfide, its absorbance in the long-wave direction is significantly increased, and the absorption band edge also moves, which can be attributed to the modification effect of gold, which also indirectly reflects the reason for the improvement of the performance of the photocatalytic composite material.

[0036] Example 2 Application of indium zinc sulfide-based composite catalyst in photocatalytic hydrogen production

[0037] The xenon lamp of Zhongjiao Jinyuan was used to test the photocatalytic hydrogen production performance of the catalyst.

[0038] The method is as follows: a photocatalytic sealed reaction cell is used as a reactor, 2 mL of triethanolamine, 6 mL of acetonitrile and 4 mL of water are used as reaction media, a xenon lamp is used as a light source, simulated sunlight is used as radiation light, 0.01 g of the prepared indium zinc sulfide-based composite catalyst and 0.01 g of ZIS are used as catalysts for photocatalytic hydrogen production, and the product is detected by gas chromatography. The detection results show that the hydrogen generation rate is 4233.5 μmol / g / h.

[0039] like Figure 5 The photocatalytic hydrogen production performance of indium zinc sulfide-based photocatalytic composite materials is shown in the figure. It can be seen from the figure that pure indium zinc sulfide has a certain hydrogen production performance, and when modified with gold, the hydrogen production performance of the composite catalyst is significantly improved, and the hydrogen generation rate reaches 4233.5μmol / g / h. This shows that the introduction of Au helps to improve the photocatalytic hydrogen production performance of indium zinc sulfide.

Claims

1. An indium zinc sulfide-based composite catalyst, characterized in that: The preparation method comprises the following steps: 1) Add a mixture of zinc source, indium source and sulfur source into a beaker, add water thereto, and stir to mix the three evenly; 2) Then the mixture is transferred to a reaction vessel for hydrothermal reaction, and after the hydrothermal reaction is completed, it is washed and dried to obtain a base catalyst; 3) Adding a gold source to the base catalyst, heating to a specified temperature, then adding a sodium citrate solution and keeping the temperature for 5 to 30 minutes, cooling, centrifuging the obtained suspension, washing, and finally drying to obtain an indium zinc sulfide-based composite catalyst.

2. An indium zinc sulfide-based composite catalyst according to claim 1, characterized in that: In step 1), the zinc source, indium source and sulfur source are respectively: zinc chloride, indium trichloride tetrahydrate and thioacetamide.

3. An indium zinc sulfide-based composite catalyst according to claim 1, characterized in that: In step 1), the molar ratio of zinc source: indium source: sulfur source is 1:2:

4.

4. An indium zinc sulfide-based composite catalyst according to claim 1, characterized in that: In step 2), the hydrothermal reaction is carried out at 180° C. for 18 to 20 hours.

5. An indium zinc sulfide-based composite catalyst according to claim 1, characterized in that: In step 3), the gold source is HAuCl4·xH2O.

6. An indium zinc sulfide-based composite catalyst according to claim 1, characterized in that: In step 3), the specified temperature is 90-95°C.

7. An indium zinc sulfide-based composite catalyst according to claim 1, characterized in that: In step 3), the mass concentration of the sodium citrate solution is 1%.

8. Use of the indium zinc sulfide-based composite catalyst according to any one of claims 1 to 7 in photocatalytic hydrogen production.

9. The use according to claim 8, characterized in that: The method is as follows: a sealed reaction pool with heat preservation is used as a reactor, water, a specified hole sacrificial agent and a co-solvent are added into the reaction system, a xenon lamp is used as a light source, simulated sunlight is used as radiation light, and the indium zinc sulfide-based composite catalyst described in claims 1-7 is used as a catalyst to carry out photocatalytic hydrogen production.

10. The use according to claim 9, characterized in that: The hole sacrificial agent is triethanolamine, and the cosolvent is acetonitrile.

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