A method for preparing a photocatalyst based on ZnIn2S4 / MoS2 type II heterojunction for water splitting to produce hydrogen and degrading antibiotic pollutants.

Abstract

This invention discloses a method for preparing a ZnIn2S4 / MoS2 type II heterojunction photocatalyst for water splitting to produce hydrogen and degrading antibiotic pollutants. The method first prepares ZnIn2S4, and then, in the presence of ZnIn2S4, adds a Mo and an S source to further convert it to ZnIn2S4 / MoS2, thereby obtaining a ZnIn2S4 / MoS2 type II heterojunction visible light photocatalyst. The ZnIn2S4 / MoS2 catalyst prepared by this invention can efficiently catalyze water splitting to produce hydrogen and degrade antibiotics under visible light. Furthermore, the preparation method is simple, low-cost, and suitable for large-scale application.

Description

Technical Field

[0001] This invention relates to the fields of green hydrogen energy and wastewater treatment technology, and in particular to a method for preparing a photocatalyst based on ZnIn2S4 / MoS2 type II heterojunction for water decomposition to produce hydrogen and degrading antibiotic pollutants. Background Technology

[0002] In the process of global industrialization, energy shortages and environmental pollution have become core bottlenecks restricting human sustainable development, making the development of clean and efficient integrated technologies for energy conversion and environmental remediation crucial. Hydrogen energy, as a zero-carbon energy carrier, has great potential to replace fossil fuels, and semiconductor photocatalytic water splitting for hydrogen production is a green pathway for its large-scale application. Meanwhile, antibiotic pollutants in wastewater pose serious hazards, and traditional treatment technologies have limited effectiveness, while photocatalytic degradation technology demonstrates unique advantages.

[0003] Heterostructure construction is an effective strategy for optimizing photocatalyst performance. Among them, type II heterojunctions are widely used in photocatalytic hydrogen production and degradation due to their simple preparation and clear charge transfer pathways. They achieve efficient separation of photogenerated carriers through band alternation, retain the redox capabilities of components, and are easier to prepare than other types of heterojunctions, making them more suitable for large-scale production.

[0004] ZnIn2S4 is a preferred photocatalytic material due to its suitable band structure, excellent visible light response, and non-toxicity and stability, possessing an inherent advantage in constructing bifunctional systems. However, single ZnIn2S4 suffers from problems such as high recombination rate of photogenerated carriers, limited active sites, and significant photocorrosion, which restricts its application. MoS2, as a two-dimensional layered material, has high electrical conductivity and abundant active sites, and can be combined with ZnIn2S4 to construct type II heterojunctions, thus optimizing its catalytic performance.

[0005] Currently, a large amount of research has been conducted both domestically and internationally on type II heterostructures, but bottlenecks remain, such as poor interfacial contact quality and material agglomeration leading to insufficient utilization of active sites. Therefore, this study focuses on the preparation and synergistic performance optimization of this heterostructure, aiming to solve existing problems, provide support for the development of highly efficient bifunctional photocatalysts, and promote the industrial application of photocatalysis technology.

[0006] Building upon existing research, developing high-performance bifunctional photocatalysts to construct synergistic systems is of great significance. This invention addresses the shortcomings of existing technologies by synthesizing a ZnIn2S4 / MoS2 type II heterojunction photocatalyst and applying it to a water splitting hydrogen production and antibiotic wastewater degradation system. This system can efficiently achieve the dual functions of hydrogen production and antibiotic pollution control, providing a new pathway for green energy production and wastewater treatment, and helping to alleviate environmental pollution and the energy crisis.

[0007] Based on the above technical background, this invention develops a method for preparing a photocatalyst based on ZnIn2S4 / MoS2 type II heterojunction for water splitting to produce hydrogen and degrading antibiotic pollutants. No related technologies have been reported. Summary of the Invention

[0008] The purpose of this invention is to solve the technical problems existing in the prior art and to provide a method for preparing a photocatalyst based on ZnIn2S4 / MoS2Ⅱ type heterojunction for water splitting to produce hydrogen and degrading antibiotic pollutants.

[0009] To achieve the above objectives, the technical solution provided by this invention is: a method for preparing a ZnIn2S4 / MoS2 type II heterojunction photocatalyst for water splitting to produce hydrogen and degrading antibiotic pollutants, characterized in that: the preparation method first prepares ZnIn2S4, and then, in the presence of ZnIn2S4, further converts it to ZnIn2S4 / MoS2 by adding a Mo source and an S source, thereby obtaining a ZnIn2S4 / MoS2 type II heterojunction visible light photocatalyst. Specifically, it includes the following steps:

[0010] Step (1): Preparation of ZnIn2S4

[0011] 0.074 g Zn(NO3)2, 0.147 g InCl3·4H2O, and 0.150 g TAA were added to 50 ml of deionized water and stirred for 30 min. After mixing thoroughly, nitric acid was added to adjust the pH to 2-3, and then the mixture was transferred to a 100 ml autoclave. The mixture was reacted at 90 °C for 8 h and then cooled to room temperature. The powder was filtered and washed with deionized water and ethanol. After vacuum drying at 60 °C for 6 h, ZnIn2S4 was obtained.

[0012] Step (2): Preparation of ZnIn2S4 / MoS2 composite material

[0013] First, add 0.100 g of ZnIn2S4 to 80 ml of deionized water and sonicate for half an hour to form a homogeneous suspension. Then, add a certain amount of Na2MoO4·2H2O and stir for one hour to allow the MoO4 to form a homogeneous suspension. 2- Ions were fully adsorbed onto the ZnIn2S4 surface, and then 80 mg of TAA was added, followed by stirring for another half hour. The resulting solution was then transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at a certain temperature for a certain period of time. After cooling to room temperature, the pale green material was collected, washed alternately with ethanol and deionized water, and dried overnight at 60°C.

[0014] Preferably, the amount of Na2MoO4·2H2O added in step (2) is in the range of 10-30 mg.

[0015] Preferably, the hydrothermal reaction temperature in step (2) is in the range of 100-200 ℃.

[0016] Preferably, the hydrothermal reaction time in step (2) is in the range of 10-20 hours.

[0017] Beneficial effects of this invention:

[0018] 1. The ZnIn2S4 / MoS2 catalyst prepared in this invention can efficiently catalyze water splitting to produce hydrogen and degrade antibiotics under visible light.

[0019] 2. The ZnIn2S4 / MoS2 catalyst prepared by this invention is simple to prepare, low in cost, and suitable for large-scale application. Attached Figure Description

[0020] 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.

[0021] Figure 1 A scanning electron microscope image of the ZnIn2S4 / MoS2 catalyst prepared in Specific Example 1 of this invention;

[0022] Figure 2 The graph shows the performance of the ZnIn2S4 / MoS2 catalyst prepared in Specific Example 2 of this invention in catalyzing water splitting to produce hydrogen under visible light.

[0023] Figure 3 The graph shows the performance of the ZnIn2S4 / MoS2 catalyst prepared in Specific Example 3 of this invention in the catalytic degradation of antibiotics under visible light. Detailed Implementation

[0024] 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

[0026] Step (1): Preparation of ZnIn2S4

[0027] 0.074 g Zn(NO3)2, 0.147 g InCl3·4H2O, and 0.150 g TAA were added to 50 mL of deionized water and stirred for 30 min. After mixing thoroughly, nitric acid was added to adjust the pH to 2-3, and then the mixture was transferred to a 100 mL autoclave. The mixture was reacted at 90 °C for 8 h and then cooled to room temperature. The powder was filtered and washed with deionized water and ethanol. After vacuum drying at 60 °C for 6 h, ZnIn2S4 was obtained.

[0028] Step (2): Preparation of ZnIn2S4 / MoS2 composite material

[0029] First, add 0.100 g of ZnIn2S4 to 80 mL of deionized water and sonicate for half an hour to form a homogeneous suspension. Then add 10 mg of Na2MoO4·2H2O and stir for one hour to allow the MoO4 to form a homogeneous suspension. 2- Ions were fully adsorbed onto the ZnIn2S4 surface, and then 80 mg of TAA was added, followed by stirring for another half hour. The resulting solution was then transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 100 °C for 10 hours. After cooling to room temperature, the pale green material was collected, washed alternately with ethanol and deionized water, and dried overnight at 60 °C. Specific Implementation Example 2

[0031] Step (1): Preparation of ZnIn2S4

[0032] 0.074 g Zn(NO3)2, 0.147 g InCl3·4H2O, and 0.150 g TAA were added to 50 mL of deionized water and stirred for 30 min until homogeneous. Nitric acid was added to adjust the pH to 2-3, and the mixture was then transferred to a 100 mL autoclave. The mixture was reacted at 90 °C for 8 h and cooled to room temperature. The powder was filtered and washed with deionized water and ethanol. ZnIn2S4 was obtained after vacuum drying at 60 °C for 6 hours.

[0033] Step (2): Preparation of ZnIn2S4 / MoS2 composite material

[0034] First, add 0.100 g of ZnIn2S4 to 80 mL of deionized water and sonicate for half an hour to form a homogeneous suspension. Then add 20 mg of Na2MoO4·2H2O and stir for one hour to allow the MoO4 to form a homogeneous suspension. 2-Ions were fully adsorbed onto the ZnIn2S4 surface, and then 80 mg of TAA was added, followed by stirring for another half hour. The resulting solution was then transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 200 °C for 12 hours. After cooling to room temperature, the pale green material was collected, washed alternately with ethanol and deionized water, and dried overnight at 60 °C. Specific Implementation Example 3

[0036] Step (1): Preparation of ZnIn2S4

[0037] 0.074 g Zn(NO3)2, 0.147 g InCl3·4H2O, and 0.150 g TAA were added to 50 mL of deionized water and stirred for 30 min. After mixing thoroughly, nitric acid was added to adjust the pH to 2-3, and then the mixture was transferred to a 100 mL autoclave. The mixture was reacted at 90 °C for 8 h and then cooled to room temperature. The powder was filtered and washed with deionized water and ethanol. After vacuum drying at 60 °C for 6 h, ZnIn2S4 was obtained.

[0038] Step (2): Preparation of ZnIn2S4 / MoS2 composite material

[0039] First, add 0.100 g of ZnIn2S4 to 80 mL of deionized water and sonicate for half an hour to form a homogeneous suspension. Then add 30 mg of Na2MoO4·2H2O and stir for one hour to allow the MoO4 to form a homogeneous suspension. 2- Ions were fully adsorbed onto the ZnIn2S4 surface, and then 80 mg of TAA was added, followed by stirring for another half hour. The resulting solution was then transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 200 °C for 16 hours. After cooling to room temperature, the pale green material was collected, washed alternately with ethanol and deionized water, and dried overnight at 60 °C. Specific Implementation Example 4

[0041] Step (1): Preparation of ZnIn2S4

[0042] 0.074 g Zn(NO3)2, 0.147 g InCl3·4H2O, and 0.150 g TAA were added to 50 mL of deionized water and stirred for 30 min. After mixing thoroughly, nitric acid was added to adjust the pH to 2-3, and then the mixture was transferred to a 100 mL autoclave. The mixture was reacted at 90 °C for 8 h and then cooled to room temperature. The powder was filtered and washed with deionized water and ethanol. After vacuum drying at 60 °C for 6 h, ZnIn2S4 was obtained.

[0043] Step (2): Preparation of ZnIn2S4 / MoS2 composite material

[0044] First, add 0.100 g of ZnIn2S4 to 80 mL of deionized water and sonicate for half an hour to form a homogeneous suspension. Then, add 30 mg of Na2MoO4·2H2O and stir for one hour to allow the MoO4 to form a homogeneous suspension. 2- Ions were fully adsorbed onto the ZnIn2S4 surface, and then 80 mg of TAA was added, followed by stirring for another half hour. The resulting solution was then transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 200 °C for 20 hours. After cooling to room temperature, the pale green material was collected, washed alternately with ethanol and deionized water, and dried overnight at 60 °C.

[0045] The ZnIn2S4 / MoS2 catalyst prepared by this invention can efficiently catalyze water splitting to produce hydrogen and degrade antibiotics under visible light. It is also simple to prepare, low in cost, and suitable for large-scale application.

[0046] Without causing conflict, those skilled in the art can freely combine and use the above-mentioned additional technical features.

[0047] 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 photocatalyst based on ZnIn2S4 / MoS2 type II heterojunction for water splitting to produce hydrogen and degrading antibiotic pollutants, characterized in that: The preparation method first prepares ZnIn2S4, and then, in the presence of ZnIn2S4, further converts it into ZnIn2S4 / MoS2 by adding a Mo source and an S source, thereby obtaining a type II heterojunction visible light photocatalyst based on ZnIn2S4 / MoS2. Specifically, it includes the following steps: Step (1): Preparation of ZnIn2S4 0.074 g Zn(NO3)2, 0.147 g InCl3·4H2O, and 0.150 g thioacetamide (TAA) were added to 50 mL of deionized water and stirred for 30 min. After mixing thoroughly, nitric acid was added to adjust the pH to 2-3, and then the mixture was transferred to a 100 mL autoclave. The mixture was reacted at 90 °C for 8 h and then cooled to room temperature. The powder was filtered and washed with deionized water and ethanol. After vacuum drying at 60 °C for 6 hours, ZnIn2S4 was obtained. Step (2): Preparation of ZnIn2S4 / MoS2 composite material First, add 0.100 g of ZnIn2S4 to 80 ml of deionized water and sonicate for half an hour to form a homogeneous suspension. Then, add a certain amount of Na2MoO4·2H2O and stir for one hour to allow the MoO4 to form a homogeneous suspension. 2- Ions were fully adsorbed onto the ZnIn2S4 surface, and then 80 mg of TAA was added, followed by stirring for another half hour. The resulting solution was then transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at a certain temperature for a certain period of time. After cooling to room temperature, the pale green material was collected, washed alternately with ethanol and deionized water, and dried overnight at 60°C.

2. The preparation method of a photocatalyst based on ZnIn2S4 / MoS2 type II heterojunction for water splitting to produce hydrogen and degrading antibiotic pollutants according to claim 1, characterized in that: The amount of Na2MoO4·2H2O added in step (2) ranges from 10 to 30 mg.

3. The preparation method of a photocatalyst based on ZnIn2S4 / MoS2 type II heterojunction for water splitting to produce hydrogen and degrading antibiotic pollutants according to claim 1, characterized in that: The range of hydrothermal reaction temperature in step (2) is 100-200 ℃.

4. The preparation method of a photocatalyst based on ZnIn2S4 / MoS2 type II heterojunction for water splitting to produce hydrogen and degrading antibiotic pollutants according to claim 1, characterized in that: The hydrothermal reaction time in step (2) is in the range of 10-20 hours.

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