Preparation and application of ZnIn2S4 heterojunction material
By preparing ZnS/ZnIn2S4 compact heterojunction materials, the problems of narrow visible light response and high photogenerated electron-hole recombination rate of traditional photocatalysts were solved, and efficient photocatalytic benzyl alcohol oxidation effect was achieved.
Patent Information
- Application Number
- CN202510596266.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-09
- Publication Date
- 2025-09-19
AI Technical Summary
Traditional photocatalysts have a narrow visible light response range, high photogenerated electron-hole recombination rate, and insufficient cyclic stability, resulting in low photocatalytic efficiency.
A one-step hydrothermal method was used to prepare ZnS/ZnIn2S4 compact heterojunction material. The electric field and surface polarization were formed to promote carrier separation, and a Z-type heterostructure was constructed to enhance the redox ability.
The photocatalytic efficiency of the photocatalyst was improved. The benzyl alcohol oxidation ability was 1.5 times that of single ZnIn2S4 in argon atmosphere and 4 times that in air atmosphere, with yields reaching 88.2% and 98.2%, respectively.
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of photocatalysis, and in particular to the design of a preparation and application of a ZnIn2S4-based material for selectively oxidizing benzyl alcohol composite material. Background Art
[0002] With the advancement of the global green chemistry wave, photocatalytic technology, as a new means of clean energy conversion, is reshaping the modern chemical industry system. Especially in the field of organic synthesis, photocatalysis achieves chemical bond breaking and recombination under mild conditions by precisely controlling photogenerated carriers. Photocatalytic benzyl alcohol conversion technology has become a key breakthrough in the field of green chemistry. As an important way to achieve green chemical transformation, the core driving force of photocatalytic technology lies in the precise control of catalysts in light energy capture, carrier separation, and surface reaction activity. However, traditional photocatalysts generally face bottlenecks such as a narrow visible light response range, a high photogenerated electron-hole recombination rate, and insufficient cyclic stability. Therefore, the efficiency of photocatalysis can be effectively improved by constructing heterojunction composite materials. Summary of the Invention
[0003] The present invention aims to develop an inexpensive, readily available, and highly efficient ZnIn2S4 heterojunction catalyst and apply it to the photocatalytic oxidation of benzyl alcohol. Compared with ZnIn2S4 alone, this composite material effectively mitigates issues such as rapid recombination of photogenerated carriers and insufficient redox capacity, thereby improving photocatalytic efficiency.
[0004] The purpose of the present invention is achieved through the following technical solutions.
[0005] A preparation and application of a ZnIn2S4-based compact heterojunction material, characterized in that the method comprises the following process steps:
[0006] Preparation of ZnIn2S4-based compact heterojunctions: Zinc nitrate, indium nitrate, and thioacetamide are mixed in deionized water and sonicated until completely dissolved. The mixture is transferred to a reactor, heated, cooled, and centrifuged to dry to obtain a series of ZnS / ZnIn2S4 catalysts. This includes the following steps:
[0007] Zinc nitrate, indium nitrate and thioacetamide were mixed in deionized water, ultrasonicated until completely dissolved, and transferred to a reactor, heated, cooled, centrifuged and dried to obtain a ZnS / ZnIn2S4 catalyst.
[0008] The molar ratio of indium nitrate to zinc nitrate in the ZnIn2S4-based composite material is 1:2 to 1:5.
[0009] The molar ratio of indium nitrate to thioacetamide in the ZnIn2S4-based composite material is 1:2 to 1:5, with the optimal ratio being 1:3.
[0010] The heating temperature is 80-100℃ and the hydrothermal time is 5-8h.
[0011] Add 10-60 mg of catalyst for every 0.1-0.5 mmol of benzyl alcohol.
[0012] The photocatalytic selective oxidation of benzyl alcohol uses LED blue light as the excitation light source.
[0013] The present invention provides a ZnIn2S4-based compact heterojunction material obtained by the above-mentioned preparation method. The catalyst is applied to the photocatalytic selective oxidation of benzyl alcohol.
[0014] Compared with the prior art, the present invention has the following beneficial effects:
[0015] (1) The present invention utilizes a one-step hydrothermal method to in situ generate a series of ZnS / ZnIn2S4 catalysts. The compact heterojunction generates an electric field and surface polarization, thereby effectively promoting carrier separation. The composite catalyst has a Z-type heterostructure, which effectively retains the redox ability of the material, thereby enhancing the photocatalytic ability.
[0016] (2) The ZnS / ZnIn2S4 catalyst prepared in this invention has an oxidation capacity for benzyl alcohol 1.5 times greater than that of a single ZnIn2S4 catalyst under an argon atmosphere. The main product is CC (including benzoin, hydrogenated benzoin, and deoxybenzoin) with a yield of 88.2%.
[0017] (3) The ZnS / ZnIn2S4 catalyst prepared in the present invention has a benzyl alcohol oxidation capacity four times greater than that of a single ZnIn2S4 catalyst in an air atmosphere. The main product is benzaldehyde with a yield of 98.2%. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 SEM images of the prepared samples, where (a) is the comparative example ZnS; (b) is the comparative example ZnIn2S4; (c) is the composite material ZnS / ZnIn2S4;
[0019] Figure 2 TEM images of the prepared samples, where (a) is the comparative example ZnS; (b) is the comparative example ZnIn2S4; (c) is the composite material ZnS / ZnIn2S4;
[0020] Figure 3 is the XRD pattern of the prepared sample;
[0021] Figure 4 is the XPS pattern of the prepared sample;
[0022] Figure 5 is the UV absorption spectrum of ZnS / ZnIn2S4 catalyst;
[0023] Figure 6 is the PL map of the prepared sample;
[0024] Figure 7 To prepare the photocurrent data of the samples;
[0025] Figure 8 To prepare samples for photocatalytic oxidation of benzyl alcohol performance test;
[0026] Table 1 shows the performance test data of the photocatalytic benzyl alcohol product of the prepared samples; DETAILED DESCRIPTION
[0027] The present invention is further described below with reference to specific embodiments.
[0028] Application Examples
[0029] The specific method for testing the selective oxidation of benzyl alcohol by the photocatalyst prepared in the present invention is:
[0030] 10 mg of the catalyst was weighed and added to 5 mL of solvent containing 10.8 mg of benzyl alcohol. After ultrasonication to achieve uniform dispersion, Ar was displaced for 10 minutes, and the reaction flask was sealed. LED light was then used for 1 hour. After completion of the reaction, the reaction solution was filtered through a 0.22 μm aqueous membrane, diluted, and analyzed by GC-MS. GC-MS parameters: (30 m × 0.32 mm × 0.25 μm); carrier gas: He; temperature program: 150-265°C, 10°C / min, 265°C hold for 1 minute. H₂ was produced during the reaction and detected using an offline gas chromatograph (GC-2014).
[0031] The conversion rate of benzyl alcohol, product yield and CC coupling product selectivity were calculated according to the following equations:
[0032]
[0033] Where n0(BA) is the number of moles of benzyl alcohol at the beginning of the experiment, n(BA) is the number of moles of benzyl alcohol at the end of the experiment, and n c (BA) represents the number of moles of benzyl alcohol converted to the target product (eg, CC coupling compound).
[0034] Example 1
[0035] A method for preparing a ZnIn2S4-based compact heterojunction material comprises the following steps:
[0036] 0.594g of zinc nitrate, 0.442g of indium nitrate, and 0.6g of thioacetamide were dissolved in 40mL of deionized water. After ultrasonication for 5min, the mixture was transferred to a reactor. The mixture was heated at 80°C for 6h. When the mixture cooled to room temperature, the yellow liquid was centrifuged at 8000rpm and then washed three times with water and ethanol respectively. The yellow powder was dried at 60°C for 4h to obtain ZnS / ZnIn2S4-1 material. The ZnS / ZnIn2S4-1 material was confirmed to be a heterojunction material based on the attached figure.
[0037] Example 2:
[0038] A method for preparing a ZnIn2S4-based compact heterojunction material comprises the following steps:
[0039] 0.891g of zinc nitrate, 0.442g of indium nitrate, and 0.9g of thioacetamide were dissolved in 40mL of deionized water. After sonication for 5 minutes, the mixture was transferred to a reactor. The mixture was heated at 80°C for 6 hours. Once cooled to room temperature, the yellow liquid was centrifuged at 8000rpm and then washed three times with water and ethanol. The resulting yellow powder was dried at 60°C for 4 hours to obtain the ZnS / ZnIn2S4-2 material.
[0040] Example 3:
[0041] A method for preparing a ZnIn2S4-based compact heterojunction material comprises the following steps:
[0042] 1.19 g of zinc nitrate, 0.442 g of indium nitrate, and 1.2 g of thioacetamide were dissolved in 40 mL of deionized water. After sonication for 5 minutes, the mixture was transferred to a reactor. The mixture was heated at 80°C for 6 hours. Once cooled to room temperature, the yellow liquid was centrifuged at 8000 rpm and then washed three times with water and ethanol. The resulting yellow powder was dried at 60°C for 4 hours to obtain the ZnS / ZnIn2S4-3 material.
[0043] Embodiment 4:
[0044] A method for preparing a ZnIn2S4-based compact heterojunction material comprises the following steps:
[0045] 1.48g of zinc nitrate, 0.442g of indium nitrate, and 1.5g of thioacetamide were dissolved in 40mL of deionized water. After sonication for 5 minutes, the mixture was transferred to a reactor. The mixture was heated at 80°C for 6 hours. Once cooled to room temperature, the yellow liquid was centrifuged at 8000rpm and then washed three times with water and ethanol. The resulting yellow powder was dried at 60°C for 4 hours to obtain the ZnS / ZnIn2S4-4 material.
[0046] Example 5:
[0047] Photocatalytic selective oxidation of benzyl alcohol: The catalyst obtained in Example 3 was added to 1 mL of acetonitrile and 4 mL of water as solvent, and the reaction was carried out under an Ar atmosphere for 1 h. Other test methods were consistent with those in Example 1.
[0048] Example 6:
[0049] Photocatalytic selective oxidation of benzyl alcohol: The catalyst obtained in Example 3 was added to 5 mL of acetonitrile as a solvent and reacted under an air atmosphere for 1 h. Other testing methods were consistent with those in Example 1.
[0050] Comparative Example 1:
[0051] A method for preparing a ZnIn2S4 material comprises the following steps:
[0052] Dissolve 0.297g of zinc nitrate, 0.442g of indium nitrate, and 0.3g of thioacetamide in 40mL of deionized water. After sonication for 5 minutes, transfer the mixture to a reactor. Heat the mixture at 80°C for 6 hours. Once cooled to room temperature, centrifuge the yellow liquid at 8000rpm and wash it three times with water and ethanol. The resulting yellow powder is dried at 60°C for 4 hours to obtain ZnIn2S4 material.
[0053] Comparative Example 2:
[0054] A method for preparing a ZnS material comprises the following steps:
[0055] Dissolve 0.297g of zinc nitrate and 0.075g of thioacetamide in 0mL of deionized water. After sonication for 5 minutes, the mixture was allowed to stand at room temperature for 12 hours. The white liquid was then centrifuged at 8000rpm and washed three times with water and ethanol, respectively. The resulting yellow powder was dried at 60°C for 4 hours to obtain the ZnS material.
[0056] Comparative Example 3:
[0057] Photocatalytic selective oxidation of benzyl alcohol: except that no catalyst was added, other conditions were the same as those in Example 1.
[0058] Comparative Example 4:
[0059] Photocatalytic selective oxidation of benzyl alcohol: except that LED irradiation was not used, other conditions were the same as those in Example 1.
[0060] Comparative Example 5:
[0061] Photocatalytic selective oxidation of benzyl alcohol: The reaction tube containing the catalyst was heated to 50° C. without LED irradiation. Other conditions were the same as those in Example 1.
[0062] Comparative Example 6:
[0063] A method for preparing a ZnIn2S4-based compact heterojunction material comprises the following steps:
[0064] 1.78g of zinc nitrate, 0.442g of indium nitrate, and 1.8g of thioacetamide were dissolved in 40mL of deionized water. After sonication for 5 minutes, the mixture was transferred to a reactor. The mixture was heated at 80°C for 6 hours. Once cooled to room temperature, the yellow liquid was centrifuged at 8000rpm and then washed three times with water and ethanol. The resulting yellow powder was dried at 60°C for 4 hours to obtain the ZnS / ZnIn2S4-5 material.
[0065] Comparative Example 7:
[0066] A method for preparing a ZnIn2S4-based compact heterojunction material comprises the following steps:
[0067] 2.08g of zinc nitrate, 0.442g of indium nitrate, and 2.1g of thioacetamide were dissolved in 40mL of deionized water. After sonication for 5 minutes, the mixture was transferred to a reactor. The mixture was heated at 80°C for 6 hours. Once cooled to room temperature, the yellow liquid was centrifuged at 8000rpm and then washed three times with water and ethanol. The resulting yellow powder was dried at 60°C for 4 hours to obtain the ZnS / ZnIn2S4-6 material.
[0068] Comparative Example 8:
[0069] A method for preparing a ZnIn2S4-based compact heterojunction material comprises the following steps:
[0070] 2.38g of zinc nitrate, 0.442g of indium nitrate, and 2.4g of thioacetamide were dissolved in 40mL of deionized water. After sonication for 5 minutes, the mixture was transferred to a reactor. The mixture was heated at 80°C for 6 hours. Once cooled to room temperature, the yellow liquid was centrifuged at 8000rpm and then washed three times with water and ethanol. The resulting yellow powder was dried at 60°C for 4 hours to obtain the ZnS / ZnIn2S4-7 material.
[0071] Performance evaluation
[0072] The photocatalytic performance and H2 generation rate of benzyl alcohol were tested using the method of the application example in Examples 1-6 and Comparative Examples 1-8. The results are shown in Table 1. The ZnIn2S4-based compact heterojunction materials prepared in Examples 1-6 can catalyze benzyl alcohol under the irradiation of LED lights. Its excellence lies in that the ZnS / ZnIn2S4 catalyst obtained in Example 3 is applied to the photocatalytic selective oxidation of benzyl alcohol, and BAD or CC products can be selectively obtained by adjusting the reaction conditions. Specifically, Example 3 has the best CC selectivity. The ZnS / ZnIn2S4 catalyst obtained in Example 3 is applied to the photocatalytic selective oxidation of benzyl alcohol. After 1 hour of reaction, the conversion rate of benzyl alcohol reaches more than 99%. The reaction rate reaches 10mmolg -1 h -1 The selectivity for the CC coupling product reached 86.2%, 2.69 times that of ZnIn2S4 alone (selectivity 32.1%). Example 6 exhibited the best BAD selectivity (up to 98.2%). Taking Example 3 as an example, compared to Comparative Examples 1-2, Example 3 significantly improved the conversion of benzyl alcohol and the selectivity for the CC coupling product. Furthermore, Comparative Examples 4-5 demonstrate that the reaction is photoinitiated. Figure 1-2 To prepare samples for SEM, Figure 2 The TEM of Example 3 includes two different lattice fringe spacings. Figure 1-3 This shows that the composite material was successfully prepared and had a tight heterojunction. Figure 4-7 The XPS, fluorescence, and photocurrent response tests for Example 3 and Comparative Examples 1-2 show that Example 3 exhibits the best photocurrent response and the slowest photogenerated hole-electron recombination rate. This is because the tight heterojunction creates a built-in electric field between ZnS and ZnIn2S4, effectively suppressing the recombination of photogenerated electrons and holes. This improves the utilization efficiency of photogenerated electrons and enhances the photocatalytic activity of benzyl alcohol.
[0073] Table 1. Photocatalytic oxidation performance test of benzyl alcohol on ZnS / ZnIn2S4 materials
[0074]
[0075]
[0076]
[0077] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art shall fall within the scope of protection defined by the claims of the present invention.
Claims
1. Application of a ZnIn2S4 heterojunction material as a catalyst in the photocatalytic selective oxidation of benzyl alcohol.
2. The use according to claim 1, characterized in that The following steps are involved: Zinc nitrate, indium nitrate and thioacetamide were mixed in deionized water, ultrasonicated until completely dissolved, and transferred to a reactor, heated, cooled, centrifuged and dried to obtain a ZnS / ZnIn2S4 catalyst.
3. The use according to claim 1, characterized in that The molar ratio of indium nitrate to zinc nitrate in the ZnIn2S4-based composite material is 1:2 to 1:
5.
4. The use according to claim 1, characterized in that The molar ratio of indium nitrate to thioacetamide in the ZnIn2S4-based composite material is 1:2 to 1:5, with the optimal ratio being 1:
3.
5. The use according to claim 1, characterized in that The heating temperature is 80-100℃ and the hydrothermal time is 5-8h.
6. The use according to claim 1, characterized in that Add 10-60 mg of catalyst for every 0.1-0.5 mmol of benzyl alcohol.
7. The use according to claim 1, characterized in that The photocatalytic selective oxidation of benzyl alcohol uses LED blue light as the excitation light source.