阅读说明：本技术 一种Co9S8/ZnIn2S4光催化产氢材料及其制备方法和应用 (Co9S8/ZnIn2S4Photocatalytic hydrogen production material and preparation method and application thereof ) 是由 魏明志 李前成 卢启芳 马迪 高兴龙 郭恩言 于 2021-10-19 设计创作，主要内容包括：本发明涉及一种Co-(9)S-(8)/ZnIn-(2)S-(4)光催化产氢材料及其制备方法和应用,属于无机光催化材料技术领域。本发明在花球状的ZnIn-(2)S-(4)材料上负载Co-(9)S-(8)颗粒从而形成异质结复合材料,具体为纳米片组成的花球并分布纳米颗粒,花球直径为200-800nm,其中八硫化九钴与四硫化二铟合锌构成异质结构。本发明在可见光的照射下,具有良好的光催化活性,复合后半导体的产氢速率最高可达12.67mmol h～(-1)g～(-1),可回收多次利用,循环稳定性良好,且不会对环境产生二次污染。(The invention relates to Co 9 S 8 /ZnIn 2 S 4 A photocatalytic hydrogen production material and a preparation method and application thereof belong to the technical field of inorganic photocatalytic materials. The invention relates to ZnIn with flower ball shape 2 S 4 Co supported on the material 9 S 8 The particles form a heterojunction composite material, specifically are spherules consisting of nanosheets and are distributed with nanoparticles, the diameter of the spherules is 200-800nm, and the cobalt nonaoctasulfide and the zinc diindisulfide form a heterostructure. The invention has good photocatalytic activity under the irradiation of visible light, and the hydrogen production rate of the semiconductor after compounding can reach 12.67mmol h at most ‑1 g ‑1 Can be recycled for multiple times, has good circulation stability, and can not generate secondary to the environmentAnd (4) pollution.)

1. Co₉S₈/ZnIn₂S₄The photocatalytic hydrogen production material is characterized in that the photocatalytic hydrogen production material is ZnIn in a flower ball shape₂S₄Co supported on the material₉S₈The particles thereby form a heterojunction composite.

2. Preparation of Co according to claim 1₉S₈/ZnIn₂S₄The method for producing the hydrogen material by photocatalysis is characterized by comprising the following steps:

(1) dissolving zinc chloride and indium chloride in N, N-Dimethylformamide (DMF), adding thioacetamide aqueous solution, stirring for 30min, transferring to a reaction kettle with a polytetrafluoroethylene lining, reacting at 160-200 ℃ for 10h, cooling to room temperature, washing with deionized water and absolute ethyl alcohol, drying at 60 ℃ for 10h, and collecting to obtain ZnIn₂S₄Flower ball;

(2) ZnIn prepared in the step (1)₂S₄Dissolving the ball flower in water, performing ultrasonic treatment for 30min, adding a cobalt source, stirring for 2h, slowly adding a sulfur source water solution, stirring until the solution is uniformly mixed, transferring the solution into a reaction kettle with a polytetrafluoroethylene lining, reacting at 120 ℃ for 10h-20h, cooling to room temperature, washing with deionized water and absolute ethyl alcohol, drying and collecting to obtain Co₉S₈/ZnIn₂S₄A photocatalytic hydrogen production material.

3. The method according to claim 2, wherein in the step (1), the molar ratio of zinc chloride to indium chloride to thioacetamide is 1:2 (4-8).

4. The method according to claim 2, wherein in the step (2), the cobalt source is cobalt chloride hexahydrate or cobalt acetate tetrahydrate.

5. The method according to claim 2, wherein in the step (2), the sulfur source is sodium sulfide nonahydrate, thioacetamide, thiourea.

6. The method of claim 2, wherein in step (2), ZnIn₂S₄The molar ratio of the cobalt source to the sulfur source is 0.237 (0.01-0.06) to 0.05-0.3.

7. The method of claim 6, wherein in step (2), ZnIn₂S₄The molar ratio of the cobalt source to the sulfur source was 0.237:0.034: 0.17.

8. Co prepared by the method of any one of claims 2 to 7₉S₈/ZnIn₂S₄The photocatalytic hydrogen production material is a flower ball composed of nano sheets and distributed with nano particles, the diameter of the flower ball is 200-800nm, and the cobalt octasulfide and the zinc tetrasulfide form a heterostructure.

9. Co as claimed in claim 1₉S₈/ZnIn₂S₄The application of the photocatalytic hydrogen production material in the photolysis of water and hydrogen.

10. Co prepared by the method of any one of claims 2 to 7₉S₈/ZnIn₂S₄The application of the photocatalytic hydrogen production material in the photolysis of water and hydrogen.

Technical Field

The invention relates to Co₉S₈/ZnIn₂S₄A photocatalytic hydrogen production material and a preparation method and application thereof belong to the technical field of inorganic photocatalytic materials.

Background

With the rapid development of industrial economy, the energy crisis and environmental problems are increasingly aggravated, and the search for new energy becomes the focus of attention of all countries. Hydrogen has the advantages of no pollution, reproducibility, high energy and the like, and becomes a research object for researchers in the world. The methods for preparing hydrogen at present include water electrolysis hydrogen production, water gas hydrogen production, biological hydrogen production and hydrocarbon hydrogen production.

The hydrogen production by photolysis of water is a novel efficient hydrogen production method, and the principle is that by utilizing illumination, photo-generated electrons generated on a conduction band of a semiconductor material are transferred to the surface of the material and react with water to generate hydrogen. In 1972, the technology was first reported to discover TiO by professors Fujishima A and Honda K, university of Tokyo, Japan₂The phenomenon that the single crystal electrode photocatalytically decomposes water to generate hydrogen gas, so that the opened water photolyzes the hot tide of hydrogen evolution. The most widely studied photolytic water semiconductor materials include transition metal sulfides (CdS, ZnS, etc.), metal oxides (ZnO, SrTiO)₃、TiO₂Etc.) and polymers (g-C)₃N₄) Etc. photocatalytic materials.

In which ZnIn₂S₄ZnIn as a ternary metal sulfide photocatalytic material for visible light absorption₂S₄Due to its good light absorption capability, the relatively narrow band gap (about 2.5eV) and the appropriate conduction band position are the hot materials for photocatalytic research. However, ZnIn₂S₄There are also some inherent drawbacks, such as: the defects of easy recombination of photo-generated electron-hole pairs, low utilization rate of visible light, low quantum efficiency and the like hinder the efficiency of hydrogen production by photocatalytic water decomposition. Against ZnIn₂S₄The conventional methods for improving (see: The Journal of Physical Chemistry C,2008,112, 16148-16155) and constructing heterojunction (see: Applied Catalysis B: Environmental, 2018)220, 542-: applied Surface Science,2021,536,147934), supporting a cocatalyst (see: applied Catalysis B: Environmental,2014, 144, 521-: journal of the American Chemical Society,2018,140,15145-15148), and the like₂S₄The photocatalytic hydrogen evolution performance of (1). However, the metal sulfide is difficult to control in shape and size, element doping is difficult to control, the lattice matching degree of heterogeneous materials is low, the heterogeneous junctions are difficult to form through tight combination, and the industrial application is limited due to the disadvantages that the precious metal raw materials are too expensive. Therefore, supporting the cocatalyst becomes a broad method for improving the photocatalytic performance of the semiconductor material

The transition metal sulfide has the advantages of wide raw material, low price, narrow band, wide light absorption range and high charge transfer efficiency, and provides more active sites for photocatalysis, wherein the research on hydrogen production by cobalt sulfide is more recently.

Disclosure of Invention

The invention aims at the problems and provides Co₉S₈/ZnIn₂S₄Photocatalytic hydrogen production material and preparation method and application thereof.

Brief description of the invention:

the invention adopts the loaded cocatalyst for modification to prepare Co with low recombination rate of photogenerated electron-hole pairs and wider light absorption range₉S₈/ZnIn₂S₄A photocatalytic hydrogen production material. The invention relates to ZnIn with flower ball shape₂S₄Co supported on the material₉S₈The particles form a heterojunction composite material, the visible light utilization rate and the separation efficiency of photo-generated electrons and holes are effectively improved, and the photolysis water-hydrogen separation efficiency is improved.

The invention achieves the following aims:

1. a load cocatalyst and a semiconductor are adopted to form a heterojunction so as to modify the heterojunction, and the recombination of a photogenerated electron-hole pair is effectively limited in a heterogeneous interface region; the formed heterostructure effectively promotes the separation of the photo-generated electron-hole pairs and improves the efficiency of water photolysis.

2. Has wider visible light absorption range and stronger photocatalytic performance, and the preparation method is simple.

Description of terms:

room temperature: having a meaning well known to those skilled in the art, generally 25. + -. 2 ℃.

Heterojunction: two different semiconductors contact the interface region formed.

Hole sacrificial agent: chemical agents that reduce the recombination of holes and photogenerated electrons by reacting with the photogenerated holes themselves, and do not act with other agents themselves.

The invention also provides Co₉S₈/ZnIn₂S₄The preparation method of the photocatalytic hydrogen production material comprises the following steps:

(1) dissolving zinc chloride and indium chloride in N, N-Dimethylformamide (DMF), adding thioacetamide aqueous solution, stirring for 30min, transferring to a reaction kettle with a polytetrafluoroethylene lining, reacting at 160-200 ℃ for 10h, cooling to room temperature, washing with deionized water and absolute ethyl alcohol, drying at 60 ℃ for 10h, and collecting to obtain ZnIn₂S₄Flower ball;

(2) ZnIn prepared in the step (1)₂S₄Dissolving the ball flower in water, performing ultrasonic treatment for 30min, adding a cobalt source, stirring for 2h, slowly adding a sulfur source water solution, stirring until the solution is uniformly mixed, transferring the solution into a reaction kettle with a polytetrafluoroethylene lining, reacting at 120 ℃ for 10h-20h, cooling to room temperature, washing with deionized water and absolute ethyl alcohol, drying and collecting to obtain Co₉S₈/ZnIn₂S₄A photocatalytic hydrogen production material.

According to the invention, in the step (1), the molar ratio of zinc chloride to indium chloride to thioacetamide is 1:2 (4-8).

Preferably, according to the invention, in step (2), the cobalt source is cobalt chloride hexahydrate or cobalt acetate tetrahydrate.

Preferably, in step (2), the sulfur source is sodium sulfide nonahydrate, thioacetamide, thiourea.

According to a preferred embodiment of the invention, in step (2), ZnIn₂S₄Mole with cobalt and sulfur sourcesThe ratio is as follows: 0.237 (0.01-0.06): (0.05-0.3); preferably 0.237:0.034: 0.17.

The invention adopts a two-step solvothermal method to prepare Co₉S₈/ZnIn₂S₄The composite material is a flower ball composed of nano-sheets and distributed with nano-particles, the diameter of the flower ball is 200-800nm, and the cobalt octasulfide and the zinc tetrasulfide form a heterostructure.

Co as mentioned above₉S₈/ZnIn₂S₄The application of the photocatalytic hydrogen production material is applied to photolysis of water and hydrogen.

All chemicals used in the present invention were equally classified as analytical grade and were not further processed.

Compared with the prior art, the invention has the following advantages:

1. co of the invention₉S₈/ZnIn₂S₄The photocatalytic hydrogen production material is obtained by two-step solvothermal method, Co₉S₈And ZnIn₂S₄Form a heterogeneous structure of ZnIn₂S₄Photo-generated electrons generated by light excitation can be transferred to Co₉S₈Therefore, the separation and transfer of the photoproduction electron-hole pairs are effectively realized; the absorption range of visible light is widened, the absorption intensity is improved, the photocatalytic activity is good under the irradiation of the visible light, and the hydrogen production rate of the semiconductor after compounding can reach 12.67mmol h at most^-1g^-1Is pure ZnIn₂S₄5.7 times of the total weight of the powder.

2. The preparation method is simple, the process equipment is simple, and the obtained Co₉S₈/ZnIn₂S₄The photocatalytic hydrogen production material has good stability.

3. Co prepared by the invention₉S₈/ZnIn₂S₄The photocatalytic hydrogen production material can be recycled for multiple times, has good circulation stability and does not produce secondary pollution to the environment.

Drawings

FIG. 1 shows Co prepared in example 1 of the present invention₉S₈/ZnIn₂S₄Photocatalytic hydrogen production material and ZnIn of comparative example 1₂S₄Base bodyX-ray diffraction pattern (XRD).

FIG. 2 shows Co prepared in example 1 of the present invention₉S₈/ZnIn₂S₄Photocatalytic hydrogen production material and ZnIn of comparative example 1₂S₄A micro-topography of the substrate; a and b are Scanning Electron Microscope (SEM) images of the samples prepared in example 1; c and d are ZnIn prepared in comparative example 1₂S₄Scanning Electron Microscope (SEM) images of the substrate.

FIG. 3 shows Co prepared in example 1 of the present invention₉S₈/ZnIn₂S₄Photocatalytic hydrogen production material and ZnIn of comparative example 1₂S₄A micro-topography of the substrate; a and b are Transmission Electron Microscopy (TEM) images of the samples prepared in example 1; c and d are ZnIn prepared in comparative example 1₂S₄Transmission Electron Microscopy (TEM) image of the matrix.

FIG. 4 shows Co prepared in example 1 of the present invention₉S₈/ZnIn₂S₄Elemental Mapping of photocatalytic hydrogen production material.

FIG. 5 shows Co prepared in example 1 of the present invention₉S₈/ZnIn₂S₄Photocatalytic hydrogen production material and ZnIn of comparative example 1₂S₄Diffuse reflection spectrogram of matrix

FIG. 6 shows the LED lamp of application example 1 with Co₉S₈/ZnIn₂S₄And ZnIn₂S₄The photolytic water evolution hydrogen rate curve of (1).

FIG. 7 shows the LED lamp of application example 1 with Co₉S₈/ZnIn₂S₄And ZnIn₂S₄The photolytic water evolution hydrogen amount-time curve of (1).

FIG. 8 shows the LED lamp of application example 1 with Co₉S₈/ZnIn₂S₄And ZnIn₂S₄Graph of the cycle performance test of (1).

Detailed Description

The invention will be further described with reference to specific embodiments, and the advantages and features of the invention will become apparent as the description proceeds. The examples are illustrative only and do not limit the scope of the present invention in any way. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, and that such changes and modifications may be made without departing from the spirit and scope of the invention.

The raw materials used in the examples are conventional raw materials, and the equipment used is conventional equipment, all of which are commercially available.

Example 1

Co₉S₈/ZnIn₂S₄The preparation method of the heterojunction photocatalytic hydrogen production material comprises the following steps:

(1) dissolving 1mmol zinc chloride and 2mmol indium chloride in 20ml DMF, adding 20ml thioacetamide aqueous solution containing 4mmol, stirring for 30min, transferring into 50ml polytetrafluoroethylene lined reaction kettle, reacting at 180 deg.C for 10h, cooling to room temperature, washing with deionized water and anhydrous ethanol, drying at 60 deg.C for 10h, and collecting to obtain ZnIn₂S₄Flower ball;

(2) 100mg of ZnIn prepared in the step (1)₂S₄Dissolving the ball flower in 20ml water, performing ultrasonic treatment for 30min, adding 0.034mmol cobalt chloride hexahydrate, stirring for 2h, slowly adding 20ml sodium sulfide aqueous solution containing 0.17mmol sodium sulfide nonahydrate, stirring until the solution is uniformly mixed, transferring to a 50ml polytetrafluoroethylene-lined reaction kettle, reacting for 20h at 120 ℃, cooling to room temperature, washing with deionized water and absolute ethyl alcohol, drying at 60 ℃ for 10h, and collecting to obtain Co₉S₈/ZnIn₂S₄A composite material.

Co obtained in this example₉S₈/ZnIn₂S₄The X-ray diffraction pattern (XRD) of the heterojunction composite material is shown in fig. 1. As can be seen from FIG. 1, the supported Co₉S₈The peak intensity and position of post XRD hardly changed because of Co₉S₈Good dispersibility and small loading capacity.

Co prepared in this example₉S₈/ZnIn₂S₄Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of the heterojunction composite are shown in fig. 2 and 3. As can be seen from FIGS. 2 and 3, the prepared nanospheres have a diameter of 200-800nm and nanoparticles are present on the nanosheetsAnd the particles are aggregated to provide more catalytic active sites for the photocatalytic reaction.

Co prepared in this example₉S₈/ZnIn₂S₄The elementary Mapping of the heterojunction composite is shown in FIG. 4, indicating Co₉S₈Successfully loaded onto ZnIn₂S₄Above.

Co prepared in this example₉S₈/ZnIn₂S₄The diffuse reflection spectrum of the heterojunction composite material is shown in fig. 6, and the heterojunction composite material has stronger light absorption capacity and wider visible light absorption range (the visible light absorption range is widened from 505nm to 570nm), so that the photocatalytic efficiency is improved.

Example 2

Co₉S₈/ZnIn₂S₄The preparation method of the heterojunction photocatalytic hydrogen production material comprises the following steps:

(1) dissolving 1mmol zinc chloride and 2mmol indium chloride in 20ml DMF, adding 20ml thioacetamide aqueous solution containing 4mmol, stirring for 30min, transferring into 50ml polytetrafluoroethylene lined reaction kettle, reacting at 160 deg.C for 10h, cooling to room temperature, washing with deionized water and anhydrous ethanol, drying at 60 deg.C for 10h, and collecting to obtain ZnIn₂S₄Flower ball;

(2) 100mg of ZnIn prepared in the step (1)₂S₄Dissolving the ball flower in 20ml water, performing ultrasonic treatment for 30min, adding 0.06mmol cobalt chloride hexahydrate, stirring for 2h, slowly adding 20ml thiourea aqueous solution containing 0.3mmol thiourea, stirring until the solution is uniformly mixed, transferring to a reaction kettle with 50ml polytetrafluoroethylene lining, reacting for 10h at 120 ℃, cooling to room temperature, washing with deionized water and absolute ethyl alcohol, drying for 10h at 60 ℃, collecting to obtain Co₉S₈/ZnIn₂S₄A composite material.

Example 3

Co₉S₈/ZnIn₂S₄The preparation method of the heterojunction photocatalytic hydrogen production material comprises the following steps:

(1) dissolving 1mmol zinc chloride and 2mmol indium chloride in 20ml DMF, adding 20ml aqueous solution containing 8mmol thioacetamide, stirring for 30min, transferring to 50ml polytetrafluoroethyleneReacting in a reaction kettle with an olefin lining at 200 ℃ for 10h, cooling to room temperature, washing with deionized water and absolute ethyl alcohol, drying at 60 ℃ for 10h, and collecting to obtain ZnIn₂S₄Flower ball;

(2) 100mg of ZnIn prepared in the step (1)₂S₄Dissolving the ball flower in 20ml water, performing ultrasonic treatment for 30min, adding 0.06mmol cobalt chloride hexahydrate, stirring for 2h, slowly adding 20ml aqueous solution containing 0.3mmol thioacetamide, stirring until the solution is uniformly mixed, transferring to a 50ml reaction kettle with a polytetrafluoroethylene lining, reacting for 15h at 120 ℃, cooling to room temperature, washing with deionized water and absolute ethyl alcohol, drying at 60 ℃ for 10h, and collecting to obtain Co₉S₈/ZnIn₂S₄A composite material.

Example 4

Co₉S₈/ZnIn₂S₄The preparation method of the heterojunction photocatalytic hydrogen production material comprises the following steps:

(1) the same as example 2;

(2) 100mg of ZnIn prepared in the step (1)₂S₄Dissolving the ball flower in 20ml water, performing ultrasonic treatment for 30min, adding 0.034mmol cobalt chloride hexahydrate, stirring for 2h, slowly adding 20ml sodium sulfide aqueous solution containing 0.17mmol sodium sulfide nonahydrate, stirring until the solution is uniformly mixed, transferring to a 50ml polytetrafluoroethylene-lined reaction kettle, reacting for 20h at 120 ℃, cooling to room temperature, washing with deionized water and absolute ethyl alcohol, drying at 60 ℃ for 10h, and collecting to obtain Co₉S₈/ZnIn₂S₄A composite material.

Comparative example 1

ZnIn₂S₄The preparation method of the photocatalytic hydrogen production material comprises the following steps:

dissolving 1mmol zinc chloride and 2mmol indium chloride in 20ml DMF, adding 20ml thioacetamide aqueous solution containing 4mmol, stirring for 30min, transferring into 50ml polytetrafluoroethylene lined reaction kettle, reacting at 180 deg.C for 10h, cooling to room temperature, washing with deionized water and anhydrous ethanol, drying at 60 deg.C for 10h, and collecting to obtain ZnIn₂S₄And (5) flower balls.

ZnIn prepared by the comparative example₂S₄Of ball-flower typeThe X-ray diffraction pattern (XRD) is shown in FIG. 1. As can be seen from FIG. 1, the sample has no other impurity peaks and is pure hexagonal ZnIn₂S₄And (5) flower balls.

ZnIn prepared by the comparative example₂S₄Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of the flower ball are shown in fig. 2 and 3. As can be seen from fig. 2 and 3, the sample has a flower-like structure composed of nanosheets.

ZnIn prepared by the comparative example₂S₄The diffuse reflection spectrum of the flower ball is shown in fig. 5, and the absorption range of visible light is limited.

Application example 1

Photolytic water evolution hydrogen test

Co prepared in example 1₉S₈/ZnIn₂S₄Composite and ZnIn prepared in comparative example 1₂S₄The flower ball is applied to a photolysis water hydrogen evolution experiment, and a light source used in the experiment is a 3W LED lamp (lambda is 460nm), and the steps are as follows:

5mg of the photocatalysts (Co) obtained in example 1 and comparative example 1 were added₉S₈/ZnIn₂S₄Pure ZnIn₂S₄) Respectively dispersing into a mixed solution containing 1ml of TEOA and 4ml of deionized water, introducing nitrogen to remove air, introducing 1ml of methane gas, and performing wax sealing; the samples were then purged with LED light (0.5ml) every 1h until 3 h. And (4) pumping the extracted gas into a gas chromatograph for analysis, and calculating the total hydrogen volume of each sample according to the ratio of methane to hydrogen.

In this application example, the performance of photolytic water hydrogen evolution of the catalysts prepared in example 1 and comparative example 1 is compared as shown in fig. 6 and 7. As can be seen from FIGS. 6 and 7, Co prepared in example 1₉S₈/ZnIn₂S₄The composite material has higher efficiency of photolysis water and hydrogen evolution, and the hydrogen production rate is ZnIn prepared in comparative example 1₂S₄Is 5.7 times higher than the hydrogen production rate, indicating that Co prepared in example 1₉S₈/ZnIn₂S₄The composite material is an excellent photocatalytic hydrogen production material.

With Co prepared in example 1₉S₈/ZnIn₂S₄The composite material was subjected to 4 cycles of hydrogen production test, and the results are shown in fig. 8. As can be seen from the figure, there was no significant reduction in the hydrogen production of the catalyst after three cycles, indicating that Co was present₉S₈/ZnIn₂S₄The composite material has good reusability.