C@zni2s4 / noble metal light-driven micro-motor catalyst, and preparation method and application thereof

Abstract

The present application relates to the field of photocatalytic hydrogen production technology, and particularly relates to a C@ZnIn2S4 / noble metal light-driven micro-motor catalyst, a preparation method and application thereof. The light-driven micro-motor catalyst comprises a hollow carbon tube and ZnIn2S4 nanosheets in-situ grown on the inner and outer surfaces of the carbon tube, and Au nanoparticles are deposited on the outer surface of the carbon tube and the surface of the ZnIn2S4 nanosheets on the outer surface, thereby forming a light-driven micro-motor catalyst with a multi-level structure of high specific surface area, high dispersion active sites and multi-functional synergy, which can more efficiently perform photocatalytic hydrogen production. The light-driven micro-motor catalyst can fully utilize visible light in a photocatalytic water decomposition system as driving force, significantly improve hydrogen production efficiency, and has good stability.

Description

Technical Field

[0001] This invention relates to the field of photocatalytic hydrogen production technology, and in particular to a C@ZnIn2S4 / noble metal photodriven micromotor catalyst, its preparation method, and its application. Background Technology

[0002] The following content in the background art refers only to information related to the present invention as understood by the inventor, and is intended to enhance the understanding of the present invention by explaining some basic technical knowledge related to the present invention. This information does not necessarily constitute knowledge known to those skilled in the art.

[0003] Energy shortages and environmental pollution have made the development of sustainable energy increasingly urgent. Converting renewable solar energy into chemical energy (such as hydrogen energy) is one of the effective ways to solve the energy crisis and environmental pollution. Photocatalytic hydrogen production is a recognized effective means of producing clean energy, and its key foundation and core challenge is the development of efficient and stable photocatalysts. Currently, conventional single photocatalysts, such as metal-based photocatalysts (including metal oxides, metal sulfides, metal phosphides, and metal carbides), carbon-based photocatalysts (including carbon quantum dots, carbon nanotubes, graphitic carbon nitride, and graphene), and alloy quantum dots, generally suffer from low hydrogen production efficiency and poor stability. This is because semiconductor photocatalysts generally suffer from weak visible light absorption, easy carrier recombination, and slow surface reactions during photocatalytic water splitting. Summary of the Invention

[0004] To address the issues of low energy conversion efficiency and insufficient stability in current photocatalytic hydrogen production, this invention discloses a C@ZnIn2S4 / noble metal photodriven micromotor catalyst, its preparation method, and its applications. This catalyst can fully utilize visible light in photocatalytic water splitting systems as the driving force, significantly improving hydrogen production efficiency and exhibiting good stability. To achieve the above-mentioned objectives, this invention discloses the following technical solutions.

[0005] First, this invention discloses a C@ZnIn2S4 / noble metal photo-driven micromotor catalyst, which includes hollow carbon nanotubes and ZnIn2S4 ultrathin nanosheets grown in situ on the inner and outer surfaces of the carbon nanotubes. Au nanoparticles are deposited on the outer surface of the carbon nanotubes and the surface of the ZnIn2S4 nanosheets on the outer surface, thereby forming a multi-level structured photo-driven micromotor catalyst with high specific surface area, highly dispersed active sites, and multifunctional synergy, which can perform photocatalytic hydrogen production more efficiently.

[0006] Secondly, this invention discloses a method for preparing a C@ZnIn2S4 / noble metal photo-driven micromotor catalyst, comprising the following steps:

[0007] (1) Preparation of hollow carbon nanotubes: Plant hair fibers with natural hollow tubular structure are subjected to pyrolysis carbonization treatment, and then the carbonization product is oxidized in strong acid to obtain -COO - Functionalized hollow carbon nanotubes.

[0008] (2) Preparation of C@ZnIn2S4: The hollow carbon nanotubes are dispersed in a precursor solution composed of an indium source, a zinc source and a sulfur source, and then heated to react. After the reaction is completed, the solid product is separated, washed and dried to obtain C@ZnIn2S4, which is a three-dimensional structure formed by in-situ growth of ZnIn2S4 nanosheets on the inner and outer surfaces of the hollow carbon nanotubes.

[0009] (3) Preparation of C@ZnIn2S4 / Au: The C@ZnIn2S4 was dispersed in ethanol to form a suspension. The suspension was then dropped onto the surface of a support and dried to form a film. The film was then vapor-deposited using a noble metal as the metal source. After completion, the product was washed and dried to obtain the C@ZnIn2S4 / noble metal photo-driven micromotor catalyst.

[0010] Further, in step (1), the plant seed hair fibers include at least one of the following: goose down vine seed hair, horned melon seed hair, kapok seed hair, dandelion seed hair, cattail seed hair, sycamore seed hair, willow / poplar seed hair, etc. These plant seed hair fibers have a natural hollow tubular structure, which is convenient for preparing hollow carbon nanotubes.

[0011] Further, in step (1), the carbonization pyrolysis temperature is 500~600℃, and the time is 1~2h. Optionally, the protective atmosphere used for the pyrolysis carbonization is an inert gas such as nitrogen or argon.

[0012] Further, in step (1), the strong acid includes at least one of nitric acid, sulfuric acid, aqua regia, etc. Optionally, the concentration of the strong acid is 1~3 M. In this invention, by treating the carbonized product with a strongly oxidizing acid, -COO can be formed on the surface of the carbonized product. - Functional groups, in order to provide more active sites.

[0013] Furthermore, in step (1), the oxidation treatment is carried out at a temperature of 60~80℃ for 6~8h.

[0014] Further, in step (2), the ratio of the hollow carbon nanotube, indium source, zinc source, and sulfur source is 20-50 mg: 1-3 mmol: 2-6 mmol: 6-10 mmol. The precursor solution is a solution formed by dissolving the indium source, zinc source, and sulfur source in a mixed solvent of water and glycerol. Optionally, the volume ratio of water to glycerol is 8:1 to 4:1.

[0015] Optionally, the indium source includes any one of indium chloride, indium acetate, indium nitrate, indium sulfate, etc.

[0016] Optionally, the zinc source includes any one of zinc chloride, zinc acetate, zinc nitrate, zinc sulfate, etc.

[0017] Optionally, the sulfur source includes any one of thioacetamide (TAA), L-cysteine, thiourea, etc.

[0018] Furthermore, in step (2), the temperature of the heating reaction is 60~100℃ and the reaction time is 2~3h.

[0019] Further, in step (2), the washing method is to wash with water and then with ethanol in sequence. The drying temperature range is 50~80℃, and the time range is 2~5h.

[0020] Further, in step (3), the ratio of C@ZnIn2S4 to ethanol is 1 mg: 5~10 ml.

[0021] Furthermore, in step (3), the drying process is performed by drying at room temperature for 20 to 24 hours.

[0022] Furthermore, the precious metal includes at least one of Au, Ag, Pt, etc.

[0023] Furthermore, in step (3), the vacuum degree of the vapor deposition process is 1~3×10⁻⁶. -3 Pa, temperature 20~40℃, time 5~20 min.

[0024] Finally, this invention discloses the application of the C@ZnIn2S4 / noble metal photodriven micromotor catalyst in photocatalytic water splitting for hydrogen production.

[0025] Compared with the prior art, the present invention has the following beneficial technical effects:

[0026] This invention selects plant seed hair fibers with a natural hollow tubular structure as a carbon source and biological template. Through calcination and strong acid oxidation in an inert atmosphere, -COOH-functionalized hollow carbon microtubes are obtained. Then, ultrathin ZnIn2S4 nanosheets are grown in situ on the inner and outer surfaces of the carbon microtubes. Finally, noble metal nanoparticles are deposited to obtain a C@ZnIn2S4 / noble metal composite nanomaterial with a three-dimensional hollow multilayered structure. Specifically, ZnIn2S4 is a narrow-bandgap two-dimensional layered material, which enables the C@ZnIn2S4 / noble metal composite nanomaterial to exhibit excellent visible light response. However, ZnIn2S4 still suffers from drawbacks such as high recombination rate of photogenerated carriers, easy aggregation, and susceptibility to photocorrosion. To address these issues, this invention introduces hollow carbon nanotubes and loads ZnIn2S4 nanosheets in situ onto the hollow carbon nanotubes. This avoids the aggregation of ZnIn2S4 nanosheets and the formation of numerous heterojunctions. This microtube framework not only improves the stability of the material and promotes the uniform dispersion of active sites but also accelerates the electron transport process, effectively overcoming the aforementioned problems.

[0027] Furthermore, this invention discovered that because the (001) crystal plane is most easily exposed during the synthesis of layered ZnIn2S4, its terminal atoms are in-plane saturated S atoms, which are inactive sites for hydrogen evolution and will affect the photocatalytic hydrogen production effect. Therefore, this invention further deposits noble metal nanoparticles on the ZnIn2S4 nanosheets. The surface plasmon enhancement effect and the heterojunction formed by the ZnIn2S4 nanosheets have stronger visible light absorption and a lower band gap. The introduction of these noble metal nanoparticles can significantly suppress the recombination of photogenerated carriers in ZnIn2S4 under illumination, thereby improving the separation and migration efficiency of photogenerated carriers and thus enhancing photocatalytic activity.

[0028] In photocatalytic water splitting for hydrogen production, under visible light irradiation, on one hand, the C@ZnIn2S4 / noble metal heterojunction absorbs solar energy and is excited to generate electrons and holes. Highly conductive hollow carbon nanotubes continuously provide electrons to ZnIn2S4 to compensate for the recombination of photogenerated electrons and holes in ZnIn2S4. Simultaneously, the noble metal nanoparticles further capture the photogenerated electrons accumulated on the conduction band of ZnIn2S4, achieving efficient electron migration during photocatalysis, which then reacts with protons (water) to produce hydrogen. On the other hand, under visible light irradiation, the photo-excited electrons of the micromotor catalyst are captured by the noble metal nanoparticles. Electrons and holes accumulate at both ends of the micromotor (ZnIn2S4 catalytic end and noble metal end), forming a gradient field that induces directional movement of the micro-water flow. This causes the micromotor itself to move in the opposite direction to the water flow, greatly enhancing the collision probability and mass transfer efficiency between the components of the system, further improving the photocatalytic hydrogen production activity. The unique three-dimensional, multi-layered open structure of the C@ZnIn2S4 / noble metal micromotor provides a high specific surface area. The system's excellent light absorption capacity, stable redox properties, fast photogenerated carrier transfer rate, and autonomous, random motion of the micromotor under illumination are the keys to the system's high efficiency and high stability. Attached Figure Description

[0029] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings, wherein:

[0030] Figure 1 The XRD pattern of the C@ZnIn2S4 / Au photo-driven micromotor catalyst prepared in Example 1 below.

[0031] Figure 2 SEM image of the C@ZnIn2S4 / Au photo-driven micromotor catalyst prepared in Example 1 below.

[0032] Figure 3 Delayed motion images and motion trajectory diagrams of the C@ZnIn2S4 / Au photo-driven micromotor catalyst prepared in Example 1 below.

[0033] Figure 4 The hydrogen production rate and hydrogen production stability of the catalysts prepared for the following examples are test results. Detailed Implementation

[0034] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they shall be used in accordance with conventional methods in the art or as per the product instructions. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. The invention will now be further described with reference to the accompanying drawings and specific embodiments. The preferred embodiments and materials described herein are for illustrative purposes only.

[0036] Example 1

[0037] A method for preparing a C@ZnIn2S4 / Au photo-driven micromotor catalyst includes the following steps:

[0038] (1) Preparation of hollow carbon tubes: Take 2g of goose down rattan fiber and place it in a tube furnace. Under N2 protection, calcine at 500℃ for 2h to obtain hollow carbon tubes.

[0039] (2) Weigh 200 mg of the hollow carbon tubes and disperse them evenly in 2M nitric acid solution. Sonicate for 30 min, reflux and stir at 80°C for 3 h, cool to room temperature, separate the hollow carbon tubes, wash with distilled water until neutral, and dry at 60°C for 4 h to obtain acidified hollow carbon tubes.

[0040] (3) Preparation of C@ZnIn2S4: Weigh 1 mmol ZnCl2, 2 mmol InCl3•4H2O, and 6 mmol TAA, respectively, and add them to a mixed solvent of 40 mL deionized water and 10 mL glycerol for ultrasonic dissolution. Then add 20 mg of the acidified hollow carbon nanotubes, continue stirring for 1 h, and transfer the resulting mixture to a round-bottom flask. React in an oil bath at 80 °C for 2 h. After the reaction is complete, cool to room temperature, filter out the solid product, wash it three times each with deionized water and ethanol, and then dry it in a drying oven at 60 °C for 3 h to obtain C@ZnIn2S4.

[0041] (4) Preparation of C@ZnIn2S4 / Au: 10 mg of the C@ZnIn2S4 was dispersed in 100 mL of ethanol to form a suspension. The suspension was dropped onto the surface of a glass slide and dried at room temperature for 24 hours to form a film after curing.

[0042] (5) Using metallic Au as the gold source, a VZZ-300 vacuum evaporator (vacuum degree of 1×10⁻⁶) was used. -3The film was vapor-deposited for 10 min at 30°C (Pa) to deposit Au nanoparticles on the surface of C@ZnIn2S4. Finally, the glass slide was ultrasonically treated in ethanol for 20 min (600W) to peel off the product. The product was then filtered out, washed three times each with deionized water and ethanol, and then dried at 60°C for 3 h to obtain the C@ZnIn2S4 / Au photo-driven micromotor catalyst.

[0043] Figure 1 The XRD pattern of the C@ZnIn2S4 / noble metal photo-driven micromotor catalyst prepared in this embodiment is shown in the figure. As can be seen from the figure, the characteristic diffraction peaks of ZnIn2S4 are sharp, indicating good crystallinity. The diffraction peaks at 2θ=21.59°, 28.33°, 46.99°, 52.26° and 55.77° correspond to the (009), (104), (110), (119) and (024) crystal planes of ZnIn2S4 (JCPDS No. 49-1562), respectively. After depositing Au nanoparticles, characteristic diffraction peaks at 2θ = 38.20°, 44.39°, 64.57°, and 77.54° were observed in the XRD pattern, corresponding to the (111), (200), (220), and (311) crystal planes of the Au nanoparticles (JCPDS No. 04-0784), respectively. These test results indicate that C@ZnIn2S4 / Au was successfully prepared in this embodiment.

[0044] Figure 2 SEM images of the C@ZnIn2S4 / Au photo-driven micromotor catalyst prepared in this embodiment are shown. (a) and (b) are macroscopic images of the goose down rattan fibers. (c) is an SEM image of the goose down rattan fibers, showing a distinct hollow tubular structure with a smooth surface, thin walls, and an outer diameter of approximately 10 μm. (d) is an SEM image of the acidified hollow carbon nanotubes, showing that the acidified hollow carbon nanotubes perfectly retain the hollow tubular structure of the fibers, with a diameter still approximately 10 μm. (e) is an SEM image of the C@ZnIn2S4, showing that an ultrathin layer of ZnIn2S4 nanosheets is grown in situ on both the inner and outer surfaces of the carbon nanotubes, with an outer diameter of approximately 13 μm. (f) is an SEM image of the C@ZnIn2S4 / Au micromotor, illustrating the deposition of Au nanoparticles, approximately 30 nm in size, in the gaps between the ZnIn2S4 nanosheets. The above test results indicate that this embodiment successfully prepared a C@ZnIn2S4 / Au photo-driven micromotor catalyst with a three-dimensional multi-level structure.

[0045] The motion of the C@ZnIn2S4 / noble metal photodriven micromotor catalyst prepared in this embodiment under different light intensities was studied, and the results are as follows: Figure 3 As shown in the figure, (a)-(d) are the motion delay images and motion trajectory diagrams of the micromotor catalyst under blue light irradiation of 3000 Lux, 6000 Lux, 12000 Lux, and 48000 Lux, respectively. It can be seen from the figures that the motion speed of the micromotor gradually increases with increasing light intensity, and its motion trajectory exhibits an irregular shape. (e) is a bar chart of the motion speed of the micromotor catalyst under different light intensities. It can be seen that the motion speed of the micromotor increases with increasing light intensity, reaching 8.3 μm / s under 48000 Lux blue light irradiation.

[0046] Example 2

[0047] A method for preparing a C@ZnIn2S4 / Pt photo-driven micromotor catalyst includes the following steps:

[0048] (1) Preparation of hollow carbon tubes: Take 2g of goose down rattan fiber and place it in a tube furnace. Under N2 protection, calcine at 600℃ for 1h to obtain hollow carbon tubes.

[0049] (2) Weigh 200mg of the hollow carbon tubes and disperse them evenly in 1M sulfuric acid solution. Sonicate for 30min, reflux and stir at 60℃ for 3h, cool to room temperature, separate the hollow carbon tubes, wash them with distilled water until neutral, and dry them at 80℃ for 2h to obtain acidified hollow carbon tubes.

[0050] (3) Preparation of C@ZnIn2S4: Weigh 1 mmol ZnCl2, 2 mmol InCl3•4H2O, and 8 mmol thiourea, respectively, and add them to a mixed solvent of 40 mL deionized water and 10 mL glycerol for ultrasonic dissolution. Then add 50 mg of the acidified hollow carbon nanotubes, continue stirring for 1 h, and transfer the resulting mixture to a round-bottom flask. React in an oil bath at 70 °C for 3 h. After the reaction is complete, cool to room temperature, filter out the solid product, wash it three times each with deionized water and ethanol, and then dry it in a drying oven at 60 °C for 3 h to obtain C@ZnIn2S4.

[0051] (4) Preparation of C@ZnIn2S4 / Pt: 10 mg of the C@ZnIn2S4 was dispersed in 50 mL of ethanol to form a suspension. The suspension was dropped onto the surface of a glass slide and dried at room temperature for 22 hours to form a film after curing.

[0052] (5) Using metallic Pt as the gold source, a VZZ-300 vacuum evaporator (vacuum degree of 1×10⁻⁶) was used. -3The film was vapor-deposited for 5 minutes at 40°C (Pa) to deposit Pt nanoparticles on the surface of C@ZnIn2S4. Finally, the glass slide was ultrasonically treated in ethanol for 30 minutes (450W) to peel off the product. The product was then filtered out, washed four times each with deionized water and ethanol, and then dried at 60°C for 3 hours to obtain the C@ZnIn2S4 / Pt photo-driven micromotor catalyst.

[0053] Example 3

[0054] A method for preparing a C@ZnIn2S4 / Ag photo-driven micromotor catalyst includes the following steps:

[0055] (1) Preparation of hollow carbon tubes: Take 2g of goose down rattan fiber and place it in a tube furnace. Calcine it at 550℃ for 1.5h under N2 protection to obtain hollow carbon tubes.

[0056] (2) Weigh 200 mg of the hollow carbon tubes and disperse them evenly in a 3M nitric acid solution. Sonicate for 30 min, reflux and stir at 100°C for 2 h, cool to room temperature, separate the hollow carbon tubes, wash them with distilled water until neutral, and dry them at 50°C for 5 h to obtain acidified hollow carbon tubes.

[0057] (3) Preparation of C@ZnIn2S4: Weigh 3 mmol ZnCl2, 6 mmol InCl3•4H2O, and 10 mmol L-cysteine, respectively, and add them to a mixed solvent of 80 mL deionized water and 10 mL glycerol for ultrasonic dissolution. Then add 30 mg of the acidified hollow carbon nanotubes, continue stirring for 1 h, and transfer the resulting mixture to a round-bottom flask. React in an oil bath at 90 °C for 2 h. After the reaction is complete, cool to room temperature, filter out the solid product, wash 5 times each with deionized water and ethanol, and then dry in a drying oven at 60 °C for 3 h to obtain C@ZnIn2S4.

[0058] (4) Preparation of C@ZnIn2S4 / Ag: 10 mg of the C@ZnIn2S4 was dispersed in 80 mL of ethanol to form a suspension. The suspension was dropped onto the surface of a glass slide and dried at room temperature for 20 hours to form a film after curing.

[0059] (5) Using metallic Ag as the gold source, a VZZ-300 vacuum evaporator (vacuum degree of 3×10⁻⁶) was used. -3The film was vapor-deposited for 20 min at 20°C (Pa) to deposit Ag nanoparticles on the surface of C@ZnIn2S4. Finally, the glass slide was ultrasonically treated in ethanol for 20 min (600W) to peel off the product. The product was then filtered out, washed three times each with deionized water and ethanol, and then dried at 60°C for 3 h to obtain the C@ZnIn2S4 / Ag photo-driven micromotor catalyst.

[0060] Example 4

[0061] A method for preparing a C@ZnIn2S4 photocatalyst includes the following steps:

[0062] (1) Preparation of hollow carbon tubes: Take 2g of goose down rattan fiber and place it in a tube furnace. Under N2 protection, calcine at 500℃ for 2h to obtain hollow carbon tubes.

[0063] (2) Weigh 200 mg of the hollow carbon tubes and disperse them evenly in 2M nitric acid solution. Sonicate for 30 min, reflux and stir at 60°C for 8 h, cool to room temperature, separate the hollow carbon tubes, wash with distilled water until neutral, and dry at 60°C for 10 h to obtain acidified hollow carbon tubes.

[0064] (3) Preparation of C@ZnIn2S4: Weigh 1 mmol ZnCl2, 2 mmol InCl3•4H2O, and 6 mmol TAA respectively, add them to a mixed solvent of 40 mL deionized water and 10 mL glycerol and sonicate to dissolve. Then add 20 mg of the acidified hollow carbon nanotubes, continue stirring for 1 h, and transfer the resulting mixture to a round-bottom flask. React in an oil bath at 80 °C for 2 h. After the reaction is complete, cool to room temperature, filter out the solid product, wash it three times each with deionized water and ethanol, and then dry it at 60 °C for 3 h to obtain C@ZnIn2S4, which is used as a catalyst for photocatalytic hydrolysis to produce hydrogen.

[0065] Example 5

[0066] A method for preparing a C / Au photocatalyst includes the following steps:

[0067] (1) Preparation of hollow carbon tubes: Take 2g of goose down rattan fiber and place it in a tube furnace. Under N2 protection, calcine at 500℃ for 2h to obtain hollow carbon tubes.

[0068] (2) Weigh 200 mg of the hollow carbon tubes and disperse them evenly in 2M nitric acid solution. Sonicate for 30 min, reflux and stir at 60°C for 8 h, cool to room temperature, separate the hollow carbon tubes, wash with distilled water until neutral, and dry at 60°C for 10 h to obtain acidified hollow carbon tubes.

[0069] (3) Preparation of C / Au: 10 mg of the acidified hollow carbon nanotubes were dispersed in 10 mL of ethanol to form a suspension. The suspension was dropped onto the surface of a glass slide and dried at room temperature for 24 hours. After curing, a film was formed. Using metallic Au as the gold source, a VZZ-300 vacuum evaporator (vacuum degree 1×10⁻⁶) was used. -3 The film was vapor-deposited for 10 minutes at 30°C (Pa) to deposit Au nanoparticles on the surface of the carbon nanotubes. Finally, the glass slide was ultrasonically treated in ethanol for 20 minutes (600W) to peel off the product. The product was then filtered out, washed three times each with deionized water and ethanol, and dried at 60°C for 3 hours. The resulting C / Au product was used as a catalyst for photocatalytic water splitting to produce hydrogen.

[0070] Example 6

[0071] A method for preparing a PP@ZnIn2S4 / Au photocatalyst includes the following steps:

[0072] (1) Weigh 200mg of commercially available polypropylene (PP) fiber (solid carbon fiber) and disperse it evenly in 2M nitric acid solution. Sonicate for 30min, reflux and stir at 60℃ for 8h, cool to room temperature, separate the hollow carbon tubes, wash with distilled water until neutral, and dry at 60℃ for 10h to obtain acidified solid PP fiber.

[0073] (2) Preparation of PP@ZnIn2S4: Weigh 1 mmol ZnCl2, 2 mmol InCl3•4H2O, and 6 mmol TAA, respectively, and add them to a mixed solvent of 40 mL deionized water and 10 mL glycerol for ultrasonic dissolution. Then add 20 mg of the acidified hollow carbon nanotubes, and continue stirring for 1 h. Transfer the resulting mixture to a round-bottom flask and react in an oil bath at 80 °C for 2 h. After the reaction is complete, cool to room temperature, filter out the solid product, wash it three times each with deionized water and ethanol, and then dry it at 60 °C for 3 h to obtain PP@ZnIn2S4.

[0074] (3) Preparation of PP@ZnIn2S4 / Au: 10 mg of the PP@ZnIn2S4 was dispersed in 10 mL of ethanol to form a suspension. The suspension was dropped onto the surface of a glass slide and dried at room temperature for 24 hours to form a film after curing.

[0075] (4) Using metallic Au as the gold source, a VZZ-300 vacuum evaporator (vacuum degree of 1×10⁻⁶) was used. -3The film layer was vapor-deposited for 10 min at 30°C (Pa) to deposit Au nanoparticles on the surface of PP@ZnIn2S4. Finally, the glass slide was ultrasonically treated in ethanol for 20 min (600W) to peel off the product from the slide. The product was then filtered out, washed three times each with deionized water and ethanol, and dried at 600°C for 3 h to obtain the PP@ZnIn2S4 / Au photocatalyst.

[0076] Example 7

[0077] A method for preparing a C@ZnIn2S4 / Au(N) photocatalyst includes the following steps:

[0078] (1) Preparation of hollow carbon tubes: Take 2g of goose down rattan fiber and place it in a tube furnace. Under N2 protection, calcine at 500℃ for 2h to obtain hollow carbon tubes.

[0079] (2) Preparation of C@ZnIn2S4(N) (N represents unacidified carbon nanotubes): Weigh 1 mmol ZnCl2, 2 mmol InCl3•4H2O, and 6 mmol TAA, respectively, and add them to a mixed solvent of 40 mL deionized water and 10 mL glycerol for ultrasonic dissolution. Then add 20 mg of the hollow carbon nanotubes, continue stirring for 1 h, and transfer the resulting mixture to a round-bottom flask. React in an oil bath at 80 °C for 2 h. After the reaction is complete, cool to room temperature, filter out the solid product, wash it three times each with deionized water and ethanol, and then dry it at 60 °C for 3 h to obtain C@ZnIn2S4(N).

[0080] (3) Preparation of C@ZnIn2S4 / Au(N): 10 mg of the C@ZnIn2S4(N) was dispersed in 10 mL of ethanol to form a suspension. The suspension was dropped onto the surface of a glass slide and dried at room temperature for 24 hours to form a film after curing.

[0081] (4) Using metallic Au as the gold source, a VZZ-300 vacuum evaporator (vacuum degree of 1×10⁻⁶) was used. -3 The film was vapor-deposited for 10 min at 30°C (Pa) to deposit Au nanoparticles on the surface of C@ZnIn2S4(N). Finally, the glass slide was ultrasonically treated in ethanol for 20 min (600W) to peel off the product. The product was then filtered out, washed three times each with deionized water and ethanol, and then dried at 60°C for 3 h to obtain the C@ZnIn2S4 / Au(N) photocatalyst.

[0082] Photocatalytic hydrogen production performance test:

[0083] The hydrogen production activity and stability of the samples were evaluated using a photocatalytic water splitting system (CEL-HXF300). First, 20 mg of photocatalyst was added to a mixture of 16 mL triethanolamine and 64 mL water, and the mixture was sonicated for 30 min to ensure homogeneity. The mixture was then transferred to a Pyrex reactor, which was placed within the photocatalytic water splitting system. Before testing, the airtightness of the apparatus was checked, and the air in the reaction system was evacuated using a vacuum pump. During the test, a 300 W Xe lamp (with a filter for λ>420 nm) was used as the light source. The temperature during the reaction was controlled at 5 °C using a cooling water system. The amount of H2 generated was detected every 1 hour using gas chromatography (GC-7920).

[0084] Figure 4 The hydrogen production rate and cycle stability of the photocatalysts prepared in Examples 1, 4-7 above. Figure 4 (a) It can be seen that, with triethanolamine as a sacrificial agent, under visible light irradiation (λ>420nm), the hydrogen production activities of C / Au (Example 5), ZnIn2S4, C@ZnIn2S4 (Example 4), PP@ZnIn2S4 / Au (Example 6), C@ZnIn2S4 / Au(N) (Example 7), and C@ZnIn2S4 / Au (Example 1) increase in that order. Among them, C@ZnIn2S4 / Au has the highest hydrogen production rate, which is approximately 19.1 mmol•h. -1 •g -1The hydrogen production rate of this catalyst is significantly higher than that of other photocatalysts. This is due, in part, to the introduction of hollow carbon nanotubes, which enhances light reflection and scattering, thereby increasing the catalyst's absorption of visible light. Furthermore, the introduction of Au nanoparticles as a co-catalyst significantly inhibits photogenerated carrier recombination under illumination, thus improving the separation and migration efficiency of photogenerated carriers and enhancing photocatalytic activity. In addition, under visible light irradiation, photoexcited electrons in the C@ZnIn2S4 / Au micromotor are captured by Au, and electrons and holes accumulate at both ends of the motor, forming a gradient field. The directional movement of the micro-water flow causes the micromotor to move in the opposite direction to the water flow, which also increases fluid disturbance and active diffusion of water molecules to some extent, promoting the collision probability between the catalyst and water molecules, thereby enhancing hydrogen production efficiency. The hydrogen production mechanism of the C@ZnIn2S4 / Au photo-driven micromotor catalyst under visible light irradiation is as follows: After absorbing the energy of sunlight, the C@ZnIn2S4 / Au heterojunction is excited to generate electrons and holes. The highly conductive hollow carbon nanotubes continuously provide electrons to ZnIn2S4 to compensate for the recombination of photogenerated electrons and holes in ZnIn2S4. Simultaneously, Au nanoparticles further capture the photogenerated electrons accumulated on the conduction band of ZnIn2S4, achieving efficient electron migration during photocatalysis, which then reacts with protons (water) to produce hydrogen. Furthermore, under visible light irradiation, because the photo-excited electrons are captured by Au, electrons and holes accumulate at the gold and non-gold ends of the micromotor catalyst, respectively, forming a gradient field that induces directional movement of the micro-water flow. This causes the micromotor catalyst itself to move in the opposite direction to the water flow, greatly enhancing the collision probability and mass transfer efficiency between the components of the system, further improving the photocatalytic hydrogen production activity. The unique three-dimensional, multi-level open structure of the C@ZnIn2S4 / Au light-driven micromotor catalyst provides a high specific surface area. The system's excellent light absorption capacity, stable redox properties, ultrafast photogenerated carrier transfer rate, and autonomous, random movement of the micromotor under illumination are the key factors for the system to achieve high efficiency and stability.

[0085] Figure 4 (b) Cyclic stability test of the C@ZnIn2S4 / Au photo-driven micromotor catalyst prepared in Example 1. It can be seen that after 16 hours of visible light irradiation, the hydrogen production rate of C@ZnIn2S4 / Au decreased slightly, but was still above 1.2 mmol, indicating that the composite material system has good resistance to photocorrosion and stability.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. Application of a C@ZnIn2S4 / noble metal light-driven micro-motor catalyst in hydrogen production by water photolysis, characterized in that, The catalyst comprises hollow carbon tubes and ZnIn2S4 nanosheets grown in-situ on the inner and outer surfaces of the carbon tubes, and noble metal nanoparticles are deposited on the outer surface of the carbon tubes and the surface of the ZnIn2S4 nanosheets on the outer surface; The preparation method of the C@ZnIn2S4 / noble metal light-driven micro-motor catalyst comprises the following steps: (1) Preparation of hollow carbon tubes: plant seed hair fibers having a hollow tubular structure are subjected to pyrolysis carbonization treatment, and then the carbonized product is subjected to oxidation treatment in a strong acid to obtain -COO - functionalized hollow carbon tubes; (2) Preparation of C@ZnIn2S4: The hollow carbon tubes are dispersed into a precursor solution composed of an indium source, a zinc source and a sulfur source, and then a heating reaction is performed. After the reaction is completed, the solid product is separated, washed, dried, and then C@ZnIn2S4 is obtained, that is, a three-dimensional structure formed by growing ZnIn2S4 nanosheets in-situ on the inner and outer surfaces of the hollow carbon tubes; (3) Preparation of C@ZnIn2S4 / noble metal: The C@ZnIn2S4 is dispersed into ethanol to form a suspension; Then the suspension is dropped on the surface of a carrier for drying treatment, and a film layer is formed after solidification. Then the film layer is subjected to evaporation treatment using a noble metal as a metal source; After the completion, the obtained product is washed and dried to obtain the C@ZnIn2S4 / noble metal light-driven micro-motor catalyst; In step (1), the plant seed hair fiber comprises at least one of the following: Radix Taxilli seed hair, Calotropis seed hair, Kapok seed hair, Dandelion seed hair, Pteroxygonum seed hair, Platanus acerifolia seed hair, and willow / poplar fluff seed hair; the strong acid comprises at least one of the following: nitric acid, sulfuric acid and aqua regia. In step (3), the noble metal comprises at least one of the following: Au, Ag and Pt.

2. The application of C@ZnIn2S4 / noble metal photocatalyst in hydrogen production by water splitting according to claim 1, characterized in that, In step (1), the carbonization pyrolysis temperature is 500-600°C, and the time is 1-2 h.

3. The use of C@ZnIn2S4 / noble metal photocatalyst in hydrogen production by water splitting according to claim 1, characterized in that, The protective atmosphere used in the pyrolysis carbonization is nitrogen or inert gas.

4. The use of C@ZnIn2S4 / noble metal photocatalyst in hydrogen production by water splitting according to claim 1, characterized in that, In step (1), the concentration of the strong acid is 1-3 M.

5. The use of C@ZnIn2S4 / noble metal photocatalyst in hydrogen production by water splitting according to claim 1, characterized in that, In step (1), the oxidation treatment temperature is 60-100°C, and the reaction time is 2-3 h.

6. The use of C@ZnIn2S4 / noble metal photocatalyst in hydrogen production by water splitting according to claim 1, characterized in that, In step (2), the ratio of the hollow carbon tubes, the indium source, the zinc source and the sulfur source is 20-50 mg: 1-3 mmol: 2-6 mmol: 6-10 mmol.

7. The use of C@ZnIn2S4 / noble metal photocatalyst in hydrogen production by water splitting according to claim 1, characterized in that, In step (2), the precursor solution is a solution formed by dissolving the indium source, the zinc source and thioacetamide in a mixed solvent of water and glycerol; the volume ratio of the water and glycerol is 8:1-4:

1.

8. The use of C@ZnIn2S4 / noble metal photocatalyst in hydrogen production by water splitting according to claim 1, characterized in that, In step (2), the indium source comprises any one of the following: indium chloride, indium acetate, indium nitrate and indium sulfate.

9. The use of C@ZnIn2S4 / noble metal photocatalyst in hydrogen production by water splitting according to claim 1, characterized in that, In step (2), the zinc source comprises any one of the following: zinc chloride, zinc acetate, zinc nitrate and zinc sulfate.

10. The use of C@ZnIn2S4 / noble metal photocatalyst in hydrogen production by water splitting according to claim 1, characterized in that, In step (2), the sulfur source comprises any one of the following: thioacetamide, L-cysteine and thiourea.

11. The use of C@ZnIn2S4 / noble metal photocatalyst in hydrogen production by water splitting according to claim 1, characterized in that, In step (2), the heating reaction temperature is 70-90°C, and the reaction time is 2-3 h.

12. The use of C@ZnIn2S4 / noble metal photocatalyst in hydrogen production by water splitting according to claim 1, characterized in that, In step (2), the washing method is to sequentially use water and ethanol for washing.

13. The use of the C@ZnIn2S4 / noble metal photocatalyst according to claim 1 in the hydrogen production by water photolysis, characterized by, In step (2), the drying temperature is 50-80°C, and the time is 2-5 h.

14. The use of the C@ZnIn2S4 / noble metal photocatalyst according to claim 1 in the hydrogen production by water photolysis, characterized by, In step (3), the ratio of the C@ZnIn2S4 and ethanol is 1 mg: 5-10 ml.

15. The use of the C@ZnIn2S4 / noble metal photocatalyst according to any one of claims 1-14 in the hydrogen production by water photolysis, characterized in that, In step (3), the drying treatment is performed at room temperature for 20-24 hours.

16. The use of the C@ZnIn2S4 / noble metal photocatalyst according to any one of claims 1 to 14 for the hydrogen production by water photolysis, characterized in that, In step (3), the vacuum degree of the evaporation treatment is 1 to 5 x 10 -3 Pa, the temperature is 20 to 40 °C, and the time is 5 to 20 min.

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