Indium zinc sulfide catalyst as well as preparation method and application thereof

Abstract

The invention discloses an indium zinc sulfide catalyst and a preparation method and application thereof, and belongs to the technical field of catalytic materials.Ultrathin indium zinc sulfide with out-of-plane piezoelectric property is prepared through a one-step hydrothermal method by adding lauryl sodium sulfate as a surfactant. The structure of the obtained S-Zn-S-In-S-In-S is different from the Janus structure of S-Mo-Se prepared by a chemical vapor deposition method and a hot selenium method in the prior art, but the structure of the obtained S-Zn-S-In-S-In-S also has asymmetry in the z direction. The preparation method provided by the invention is a one-step hydrothermal method, the energy consumption is low, and the preparation process is greatly simplified. In addition, by adding SDS, the sulfur vacancy of ZnIn2S4 can be effectively increased, the hydrogen production barrier of the ZnIn2S4 (001) crystal face is optimized, the (001) face is activated as a hydrogen production active site, the carrier migration pathway is shortened, and then light-piezoelectric synergistic catalysis is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of catalytic materials, and in particular to an indium zinc sulfide catalyst and a preparation method and application thereof. Background Art

[0002] As the global demand for clean and renewable energy continues to rise, finding efficient methods for hydrogen production has become increasingly urgent. Research on photocatalytic hydrogen evolution is crucial in the search for sustainable energy solutions. Photocatalytic hydrogen evolution provides a promising pathway to use solar energy to drive the conversion of water into hydrogen fuel, which is a clean and abundant source of energy.

[0003] Single photocatalysis still has the problem of low light conversion rate. The strategy of using other catalytic synergistic catalysis is an effective strategy to further improve the photocatalytic performance. In recent years, researchers have used piezoelectric catalysis to synergize photocatalysis to separate photogenerated carriers. Piezoelectric catalytic semiconductors deform under the action of external forces, resulting in relative displacement of positive and negative charge centers and electric polarization. MoS 2 , WS 2 When there are odd-numbered layers of traditional two-dimensional transition metal sulfides, there is usually a natural symmetry breaking in the in-plane direction, so a piezoelectric effect will be generated in the plane. When the piezoelectric field is in the in-plane direction, the driving force of the piezoelectric field on the charge migration is along the layer instead of perpendicular to the layer direction, resulting in a too long migration path for the photogenerated charge, thus limiting the piezoelectric-photocatalytic efficiency of the two-dimensional material.

[0004] Janus materials refer to materials in which different types of chalcogen atoms are connected by covalent bonds on both sides of transition metal atoms, thus breaking the out-of-plane mirror symmetry of traditional materials. Due to the asymmetry of the upper and lower surfaces, the positive and negative charge centers do not coincide, thus generating a vertical dipole moment, thus having out-of-plane piezoelectricity. MoSSe is a typical Janus material, and its preparation method is to make a single layer of MoS 2 All the S atoms in the top layer of the crystal were replaced with Se atoms, and a single-layer MoSSe with a Janus structure was successfully synthesized. Its atomic layout makes the single-layer MoS 2 The structural symmetry of the upper and lower surfaces is destroyed, resulting in a dipole moment in the vertical direction, which has an out-of-plane piezoelectric effect. However, MoSSe is prepared by chemical vapor deposition and thermal selenization, which has a complex process and high requirements for equipment. Therefore, the development of two-dimensional photocatalytic materials with out-of-plane piezoelectric effect and simple synthesis similar to the Janus structure is of great significance for improving the practical application of photocatalytic hydrogen production.

[0005] Hexagonal zinc indium sulfide (ZnIn 2 S 4 ) is a member of the two-dimensional transition metal sulfide, composed of InS 6Octahedron and ZnS 4 and InS 4 Tetrahedrons are connected at the same angle to form a layered structure. The layers are connected by van der Waals forces. The out-of-plane direction does not have spatial inversion symmetry, and the upper and lower surfaces of ZnS 4 and InS 4 There is a large electronegativity difference between the tetrahedra, making single-layer or few-layer ZnIn 2 S 4 It shows out-of-plane piezoelectric properties similar to those of the Janus structure. 2 S 4 The (001) crystal plane is an inert plane for hydrogen production, that is, after the carriers migrate to the (001) crystal plane, they still need to further migrate to the edge active sites, thus limiting the catalytic process of photocatalytic hydrogen evolution. Summary of the invention

[0006] The present invention provides an indium zinc sulfide catalyst and a preparation method and application thereof. 2 S 4 Sodium dodecyl sulfate (SDS) was introduced into the micron-shaped ZnIn 2 S 4 regulated into nanosheets. Meanwhile, the introduction of SDS leads to the 2 S 4 S vacancies appear on the (001) plane of the photocatalyst. The S vacancies can regulate the electronic properties of the surrounding atoms, making the surrounding atoms active sites for hydrogen production, shortening the migration path of charge carriers, achieving photo-piezoelectric catalytic synergy, and accelerating the catalytic reaction process.

[0007] The first object of the present invention is to provide a method for preparing an indium zinc sulfide catalyst, characterized in that it comprises the following steps:

[0008] Zn 2+ Source, In 3+ The catalyst is prepared by using a one-step hydrothermal method with a source of 2-nitrogen and thioacetamide as raw materials, sodium dodecyl sulfate as a surfactant, and ethylene glycol aqueous solution as a solvent to obtain indium zinc sulfide and introduce sulfur vacancies into the (001) face of the indium zinc sulfide.

[0009] As a preferred embodiment, the mass ratio of thioacetamide to sodium dodecyl sulfate is 1:1-3.

[0010] As a preferred embodiment, the Zn 2+ Source, In 3+ The molar ratio of the source to thioacetamide is 0.9-1.1:2:4.

[0011] As a preferred embodiment, in the aqueous solution of ethylene glycol, the volume ratio of ethylene glycol to water is 0.8-1.2:5.

[0012] As a preferred embodiment, Zn 2+ Source, In 3+ The source and sodium dodecyl sulfate are added to an ethylene glycol aqueous solution to obtain a mixed solution, thioacetamide is dispersed in the mixed solution, and a hydrothermal reaction is carried out at 110 to 130° C. to obtain an indium zinc sulfide catalyst.

[0013] As a preferred embodiment, the hydrothermal reaction time is 10 to 15 hours.

[0014] As a preferred embodiment, after the hydrothermal reaction is completed, a crude product is obtained, the crude product is washed alternately by centrifugation with deionized water and ethanol for 6 times, and vacuum dried at 55-60° C. for 2 h to obtain an indium zinc sulfide catalyst.

[0015] As a preferred embodiment, the Zn 2+ The source is zinc chloride or zinc nitrate, the In 3+ The source is indium chloride tetrahydrate.

[0016] The second object of the present invention is to provide an indium zinc sulfide catalyst prepared by the above preparation method.

[0017] The third object of the present invention is to provide an application of the above-mentioned indium zinc sulfide catalyst in photo-piezoelectric catalytic decomposition of water to produce hydrogen.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The invention provides an indium zinc sulfide catalyst and a preparation method and application thereof, wherein Zn 2+ Source, In 3+ The method comprises the following steps: using a one-step hydrothermal method to obtain indium zinc sulfide by using a source and thioacetamide as raw materials, sodium dodecyl sulfate as a surfactant, and an ethylene glycol aqueous solution as a solvent, and introducing a sulfur vacancy (S vacancy) into the (001) face of the indium zinc sulfide to obtain an indium zinc sulfide catalyst.

[0020] The present invention prepares ultra-thin indium zinc sulfide with out-of-plane piezoelectric properties by adding sodium dodecyl sulfate (SDS) as a surfactant through a one-step hydrothermal method. The structure of the obtained S-Zn-S-In-S-In-S is different from the Janus structure of S-Mo-Se prepared by chemical vapor deposition and thermal selenium method in the prior art, but also has z-direction asymmetry. The preparation method of the present invention is a one-step hydrothermal method, with low energy consumption and greatly simplified preparation process. In addition, the addition of SDS in the present invention can effectively increase the ZnIn 2 S4 sulfur vacancies, optimizing ZnIn 2 S 4 The (001) crystal plane has a hydrogen production barrier, activating the (001) plane as a hydrogen production active site, shortening the carrier migration path, and thus achieving photo-piezoelectric synergistic catalysis.

[0021] The present invention adjusts the morphology of indium zinc sulfide by adjusting the dosage of the surfactant SDS, and can also regulate the concentration of sulfur vacancies, thereby achieving the synergistic effect of photocatalysis and piezoelectric catalysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 X-ray diffraction patterns of indium zinc sulfide (ZIS-bulk) prepared in comparative example 1 of the present invention, indium zinc sulfide catalyst (ZIS-150SDS) prepared in example 1, indium zinc sulfide catalyst (ZIS-300SDS) prepared in example 2, and indium zinc sulfide catalyst (ZIS-450SDS) prepared in example 3.

[0023] Figure 2 The scanning electron microscope images are of the indium zinc sulfide catalysts prepared in Comparative Example 1 and Examples 1 to 3 of the present invention; wherein, Figure a is the indium zinc sulfide (ZIS-bulk) prepared in Comparative Example 1, Figure b is the indium zinc sulfide catalyst (ZIS-150SDS) prepared in Example 1, Figure c is the indium zinc sulfide catalyst (ZIS-300SDS) prepared in Example 2, and Figure d is the indium zinc sulfide catalyst (ZIS-450SDS) prepared in Example 3.

[0024] Figure 3 These are transmission electron microscope test images of the indium zinc sulfide catalysts prepared in Comparative Example 1 and Example 2 of the present invention; wherein, Figure a is the indium zinc sulfide (ZIS-bulk) prepared in Comparative Example 1, and Figure b is the indium zinc sulfide catalyst (ZIS-300SDS) prepared in Example 2.

[0025] Figure 4 This is an atomic force microscope image of the zinc indium sulfide catalyst (ZIS-300SDS) prepared in Example 2 of the present invention, wherein Figure a is an atomic force microscope image and Figure b is a height distribution image.

[0026] Figure 5 The electron paramagnetic resonance spectra of the indium zinc sulfide (ZIS-bulk) prepared in Comparative Example 1 of the present invention and the indium zinc sulfide catalyst (ZIS-300SDS) prepared in Example 2.

[0027] Figure 6The indium zinc sulfide (ZIS-bulk) prepared in comparative example 1 of the present invention, the indium zinc sulfide catalyst (ZIS-150SDS) prepared in example 1, the indium zinc sulfide catalyst (ZIS-300SDS) prepared in example 2, and the indium zinc sulfide catalyst (ZIS-450SDS) prepared in example 3 were tested for full water decomposition and hydrogen production.

[0028] Figure 7 The performance comparison diagram of zinc indium sulfide (ZIS-bulk) prepared in comparative example 1 of the present invention and zinc indium sulfide catalyst (ZIS-300SDS) prepared in example 2 under light, ultrasound, (the algebraic sum of light and ultrasound performance) and light-ultrasound synergistic catalytic decomposition of water to produce hydrogen.

[0029] Figure 8 This is a performance comparison chart of hydrogen production within 2.5 hours between zinc indium sulfide (ZIS-bulk) prepared in comparative example 1 of the present invention and zinc indium sulfide catalyst (ZIS-300SDS) prepared in example 2.

[0030] Fig. 9 This is a piezoelectric-photocatalytic hydrogen production cycle stability diagram of the indium zinc sulfide catalyst prepared in Example 2 of the present invention.

[0031] Fig.10 It is the UV-visible absorption spectra of the zinc indium sulfide (ZIS-bulk) prepared in comparative example 1 of the present invention and the zinc indium sulfide catalyst (ZIS-300SDS) prepared in example 2.

[0032] Fig.11 This is a piezoelectric force microscope (PFM) image of the indium zinc sulfide catalyst prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention and implement it, the present invention is further described below in conjunction with specific embodiments and drawings, but the embodiments are not intended to limit the present invention. The following test methods and detection methods, unless otherwise specified, are conventional methods; the reagents and raw materials, unless otherwise specified, are commercially available.

[0034] The background technology of the present invention mentions that ZnIn obtained by the existing preparation method 2 S 4 The (001) crystal plane is an inert plane for hydrogen production, that is, after the carriers migrate to the (001) crystal plane, they still need to further migrate to the edge active sites, thereby limiting the catalytic process of photocatalytic hydrogen evolution. Based on the above technical problems, the present invention provides an indium zinc sulfide catalyst and a preparation method and application thereof.

[0035] The technical contents of the present invention are analyzed and explained in detail below.

[0036] The present invention provides a method for preparing an indium zinc sulfide catalyst, comprising the following steps:

[0037] Zn 2+ Source, In 3+ The indium zinc sulfide catalyst is obtained by using a one-step hydrothermal method with a source and thioacetamide as raw materials, sodium dodecyl sulfate as a surfactant, and an ethylene glycol aqueous solution as a solvent; and sulfur vacancies are introduced into the (001) face of the indium zinc sulfide. The Zn 2+ The source is zinc chloride or zinc nitrate, the In 3+ The source is indium chloride tetrahydrate.

[0038] In the above technical solution, by 2 S 4 Sodium dodecyl sulfate was introduced into the micron-shaped ZnIn 2 S 4 regulated into nanosheets, and the introduction of SDS leads to the 2 S 4 S vacancies appear on the (001) plane of the photocatalyst. The S vacancies can regulate the electronic properties of the surrounding atoms, making the surrounding atoms active sites for hydrogen production, shortening the migration path of charge carriers, and realizing photo-piezoelectric catalytic synergy.

[0039] It should be emphasized that the mass ratio of thioacetamide to sodium dodecyl sulfate is 1:1-3. By adjusting the amount of sodium dodecyl sulfate, not only the morphology of indium zinc sulfide can be adjusted, but also the concentration of sulfur vacancies can be regulated, thereby further realizing the synergistic effect of photocatalysis and piezoelectric catalysis. In addition, the performance of the catalyst is directly related to the amount of SDS used. Too little SDS will make ZnIn 2 S 4 The morphological transformation is not complete, and the performance improvement is not significant. However, if the SDS content is too high, ZnIn 2 S 4 The excessive S vacancy concentration in the ZIS destroys the lattice of the ZIS and causes the performance to deteriorate.

[0040] In order to obtain indium zinc sulfide with higher yield and purity, the Zn 2+ Source, In 3+ The molar ratio of Zn to thioacetamide is 0.9-1.1:2:4. 2+ If the source is too high, greater than 1.1 here, zinc sulfide will be generated. 2+ If the source is too low, less than 0.9 here, indium sulfide phase will be generated, Zn 2+ The ratio of the source is 0.9-1.1, which can ensure that the generated zinc sulfide and indium sulfide do not affect the generation of indium zinc sulfide. 2+When the ratio of the source is 1, the yield of indium zinc sulfide is the highest and the impurities are the least.

[0041] It should be noted that in the aqueous solution of ethylene glycol, the volume ratio of ethylene glycol to water is 0.8 to 1.2:5. Ethylene glycol is used as a solvent, but its dosage will affect the performance of the product. It can promote the formation of indium zinc sulfide in the hydrothermal reaction. The addition of ethylene glycol can inhibit the growth of some crystal faces, thereby changing the morphology into a flower ball shape. After adding sodium dodecyl sulfate as a surfactant, the morphology is changed to a sheet shape, thereby obtaining the target morphology.

[0042] As a preferred embodiment, Zn 2+ Source, In 3+ The source and sodium dodecyl sulfate are added to an ethylene glycol aqueous solution to obtain a mixed solution, thioacetamide is dispersed in the mixed solution, and a hydrothermal reaction is performed at 110 to 130° C. for 10 to 15 hours to obtain an indium zinc sulfide catalyst. If the temperature of the hydrothermal reaction is too low, the target product cannot be generated, and if the temperature of the hydrothermal reaction is too high, the morphology of the indium zinc sulfide catalyst will be affected.

[0043] In order to further obtain a higher purity indium zinc sulfide catalyst, after the hydrothermal reaction is completed, a crude product is obtained, the crude product is washed alternately by centrifugation with deionized water and ethanol for 6 times, and vacuum dried at 55-60° C. for 2 hours to obtain an indium zinc sulfide catalyst.

[0044] The technical effects of the present invention are described below in conjunction with specific embodiments.

[0045] Example 1

[0046] A method for preparing an indium zinc sulfide catalyst comprises the following steps:

[0047] 136 mg zinc chloride, 293 mg indium chloride tetrahydrate and 150 mg sodium dodecyl sulfate were dissolved in ethylene glycol aqueous solution (ethylene glycol: water = 1:5) and stirred, and then 150 mg thioacetamide was added and stirred for 30 min, then transferred to the inner lining of a polytetrafluoroethylene reactor and placed in an oven at 120°C for 12 h. After cooling naturally to room temperature, the obtained precipitate was washed alternately by centrifugation with deionized water and ethanol for 6 times, and vacuum dried at 60°C for 2 h to obtain an indium zinc sulfide catalyst, which was recorded as ZIS-150SDS.

[0048] Example 2

[0049] A method for preparing an indium zinc sulfide catalyst comprises the following steps:

[0050] 136 mg zinc chloride, 293 mg indium chloride tetrahydrate and 300 mg sodium dodecyl sulfate were dissolved in ethylene glycol aqueous solution (ethylene glycol: water = 1:5) and stirred, and then 150 mg thioacetamide was added and stirred for 30 min, then transferred to the inner lining of a polytetrafluoroethylene reactor and placed in an oven at 120°C for 12 h. After cooling naturally to room temperature, the obtained precipitate was washed alternately by centrifugation with deionized water and ethanol for 6 times, and vacuum dried at 60°C for 2 h to obtain an indium zinc sulfide catalyst, which was recorded as ZIS-300SDS.

[0051] Example 3

[0052] A method for preparing an indium zinc sulfide catalyst comprises the following steps:

[0053] 136 mg zinc chloride, 293 mg indium chloride tetrahydrate and 450 mg sodium dodecyl sulfate were dissolved in an ethylene glycol aqueous solution (ethylene glycol: water = 1:5) and stirred, and then 150 mg thioacetamide was added and stirred for 30 min, then transferred to the inner lining of a polytetrafluoroethylene reactor and placed in an oven at 120°C for 12 h. After cooling naturally to room temperature, the obtained precipitate was washed alternately by centrifugation with deionized water and ethanol for 6 times, and vacuum dried at 60°C for 2 h to obtain an indium zinc sulfide catalyst, which was recorded as ZIS-450SDS.

[0054] In order to further demonstrate the technical effect of the present invention, the present invention also sets a comparative example, which is as follows:

[0055] Comparative Example 1

[0056] Compared with Example 1, the difference is that no sodium dodecyl sulfate is added, and the zinc source, indium source and thioacetamide (TAA) are directly dispersed in the ethylene glycol aqueous solution, and then the hot water reaction is carried out.

[0057] A method for preparing an indium zinc sulfide catalyst comprises the following steps:

[0058] 136 mg of zinc chloride and 293 mg of indium chloride tetrahydrate were dissolved in an ethylene glycol aqueous solution (ethylene glycol: water = 1:5) and stirred. Then 150 mg of thioacetamide was added and stirred for 30 min, then transferred to a polytetrafluoroethylene reactor lining and placed in an oven at 120°C for 12 h. After cooling naturally to room temperature, the obtained precipitate was washed alternately by centrifugation with deionized water and ethanol for 6 times, and vacuum dried at 60°C for 2 h to obtain an indium zinc sulfide catalyst, which was recorded as ZIS-bulk.

[0059] The performance of the indium zinc sulfide catalysts prepared in Examples 1 to 3 and Comparative Example 1 was tested, and the specific process and results are as follows:

[0060] 1. X-ray diffraction test

[0061] The present invention takes ZIS-150SDS prepared in Example 1, ZIS-300SDS prepared in Example 2, ZIS-450SDS prepared in Example 3, and ZIS-bulk prepared in Comparative Example 1 as examples, and performs X-ray diffraction tests on them respectively, and the test results are Figure 1 shown.

[0062] Depend on Figure 1 It can be seen that all characteristic diffraction peaks can correspond to the hexagonal ZnIn 2 S 4 (JCPDS No.65-2023), the surfactant did not change the crystal structure of ZIS. Among them, the diffraction peaks with diffraction angles of 21.6°, 27.7°, and 47.2° correspond to the (006), (102), and (110) crystal planes, respectively, and the diffraction peak intensity increased significantly after the addition of the surfactant SDS, indicating that the sample exposed more crystal planes, resulting in an increase in the diffraction intensity. With the increase of the surfactant SDS, the diffraction peak intensity gradually decreased, mainly due to the increase in the concentration of sulfur vacancies, which reduced the crystallinity of the sample.

[0063] 2. Scanning electron microscope test

[0064] The present invention takes the ZIS-150SDS prepared in Example 1, the ZIS-300SDS prepared in Example 2, the ZIS-450SDS prepared in Example 3, and the ZIS-bulk prepared in Comparative Example 1 as examples, and performs scanning electron microscope tests on them respectively, and the test results are as follows: Figure 2 shown.

[0065] Depend on Figure 2 It can be seen that after adding SDS, the microscopic morphology of ZIS gradually changes from micron flower balls to nanosheets, and the morphology of the ZIS-SDS300 sample is an ultra-thin lamellar structure. When the SDS content is 450, the sample begins to agglomerate and is a mixture of nanosheets and small microspheres.

[0066] 3. Transmission electron microscopy test

[0067] Taking the ZIS-300SDS prepared in Example 2 of the present invention and the ZIS-bulk prepared in Comparative Example 1 as examples, transmission electron microscope tests were performed on them respectively, and the test results Figure 3 shown.

[0068] ZIS-bulk is a micron flower ball, and since electrons cannot penetrate the micron flower ball, it appears as a black ball. ZIS-300SDS is an ultra-thin sheet.

[0069] 4. Atomic force microscope (AFM) test

[0070] Taking the ZIS-300SDS prepared in Example 2 of the present invention as an example, an atomic force microscope test was performed on it, and the test results are as follows: Figure 4 shown.

[0071] Depend on Figure 4 It can be seen that ZIS-SDS shows ultrathin lamellae stacking with an average lamella thickness of about 5 nm, which again indicates that ZIS-300SDS is an ultrathin nanosheet configuration.

[0072] 5. Electron paramagnetic resonance test

[0073] Taking the ZIS-300SDS prepared in Example 2 of the present invention and the ZIS-bulk prepared in Comparative Example 1 as examples, electron paramagnetic resonance tests were performed on them respectively. Figure 5 shown.

[0074] The results show that ZIS-300SDS has a stronger EPR signal, indicating that the S vacancy concentration in ZIS-300SDS is significantly increased.

[0075] 6. Piezoelectric-photocatalytic water decomposition hydrogen production performance test

[0076] Taking the ZIS-150SDS prepared in Example 1 of the present invention, the ZIS-300SDS prepared in Example 2, the ZIS-450SDS prepared in Example 3, and the ZIS-bulk prepared in Comparative Example 1 as examples, the piezoelectric, optical, and piezoelectric-photocatalytic water decomposition hydrogen production performance tests were performed on them, and the test methods are as follows:

[0077] 10 mg of indium zinc sulfide catalyst sample was dispersed in 15 mL of ultrapure water and transferred to a 50 mL quartz test tube. High-purity argon was introduced for 30 minutes to exclude air and dissolved gases, and then the quartz tube was sealed with a rubber stopper and a plastic film. The test tube was placed in an ultrasonic machine (KQ2200DE CNC ultrasonic cleaner) for ultrasonication, and the sample was simultaneously irradiated with a xenon lamp light source (PL-X300DUV) to excite the sample. Every 30 minutes, a micro-injector was used to sample the amount of hydrogen produced and the gas chromatography was used to detect the amount of hydrogen produced to obtain the piezoelectric-photocatalytic performance of the sample. Similarly, the photocatalytic performance and piezoelectric catalytic performance were tested under the conditions of no ultrasound and no light, respectively.

[0078] Figure 6 This is the curve of hydrogen production of piezoelectric-photocatalyst changing with time.

[0079] from Figure 6 It can be seen that under the simultaneous action of light and ultrasound, the performance of the samples containing SDS surfactant in the complete water splitting and hydrogen production is significantly improved, and the performance of ZIS-300SDS is the best, reaching 593 μmol g -1 h -1, is ZIS-bulk (246 μmol g -1 h -1 ) is 2.41 times.

[0080] Figure 7 and Figure 8 The performance graphs of ZIS-bulk and ZIS-300SDS samples under light, ultrasound, (the algebraic sum of light and ultrasound performance) and light-ultrasound synergistic hydrogen production are shown. It can be clearly seen that the performance of ZIS-300SDS under the synergistic effect of light and ultrasound is significantly higher than the algebraic sum of the performance of light and ultrasound, while the performance of ZIS-bulk sample under the synergistic effect of light and ultrasound is only slightly higher than the algebraic sum of the two separate tests. This indicates that in the ZIS-300SDS sample, light and ultrasound synergize through sulfur vacancies to further enhance the sample performance.

[0081] 7. Piezoelectric-photocatalytic hydrogen production cycle stability test

[0082] Taking the ZIS-300SDS prepared in Example 2 of the present invention as an example, the piezoelectric-photocatalytic hydrogen production cycle stability when it is used as a catalyst is tested, and the test method is as follows:

[0083] 10 mg of the catalyst sample was dispersed in 15 mL of ultrapure water and transferred to a 50 mL quartz test tube. High-purity argon was introduced for 30 min to exclude air and dissolved gases, and then the quartz tube was sealed with a rubber stopper and a plastic film. The test tube was placed in an ultrasonic machine (KQ2200DE CNC ultrasonic cleaner) for ultrasonication, and the sample was simultaneously irradiated with a xenon light source (PL-X300DUV) to excite the sample. The amount of hydrogen produced was detected by gas chromatography using a micro-injector every 30 min. After each test for 2.5 h, the catalyst was centrifuged and redispersed in 15 mL of ultrapure water to repeat the above operation to obtain the piezoelectric-photocatalytic cycle stability of the sample.

[0084] Fig. 9 The results showed that the photocatalytic activity of the ZIS-300SDS sample remained at a high level during continuous testing for more than 10 hours.

[0085] 8. Ultraviolet-visible (UV-vis) spectroscopic test

[0086] Taking the ZIS-300SDS prepared in Example 2 of the present invention as an example, a UV-vis DRS test was performed on it.

[0087] Fig.10The UV-visible spectra of ZIS-bulk and ZIS-300SDS samples. ZIS-bulk shows good visible light response, with an absorption band edge around 550nm. Due to the quantum effect caused by its size, the absorption band edge of ZIS-300SDS sample is blue-shifted compared with that of ZIS-bulk sample. And the tailing absorption of ZIS-300SDS sample above 600nm is significantly enhanced, indicating that the presence of S vacancies in ZIS-300SDS sample promotes the localized state absorption of the sample.

[0088] 9. Piezoelectric force microscope (PFM) test

[0089] Taking the ZIS-300SDS prepared in Example 2 of the present invention as an example, an atomic force microscopy test was performed on it.

[0090] Fig.11 This is the PFM image of the ZIS-300SDS sample. The vertical piezoelectric coefficient of ZIS-300SDS is about 13.9 pm / V, indicating that it has a good piezoelectric response.

[0091] In summary, the present invention is based on ZnIn 2 S 4 Sodium dodecyl sulfate was introduced into the micron-shaped ZnIn 2 S 4 regulated into nanosheets, and the introduction of SDS leads to the 2 S 4 S vacancies appear on the (001) plane of the photocatalyst. The S vacancies can regulate the electronic properties of the surrounding atoms, making the surrounding atoms active sites for hydrogen production, shortening the migration path of charge carriers, and realizing photo-piezoelectric catalytic synergy.

[0092] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing an indium zinc sulfide catalyst, characterized in that: The following steps are involved: Zn 2+ Source, In 3+ The catalyst is prepared by using a one-step hydrothermal method with a source of 2-nitrogen and thioacetamide as raw materials, sodium dodecyl sulfate as a surfactant, and ethylene glycol aqueous solution as a solvent to obtain indium zinc sulfide and introduce sulfur vacancies into the (001) face of the indium zinc sulfide.

2. The preparation method according to claim 1, characterized in that: The mass ratio of thioacetamide to sodium dodecyl sulfate is 1:1-3.

3. The preparation method according to claim 1, characterized in that: The Zn 2+ Source, In 3+ The molar ratio of the source to thioacetamide is 0.9-1.1:2:

4.

4. The preparation method according to claim 1, characterized in that: In the aqueous solution of ethylene glycol, the volume ratio of ethylene glycol to water is 0.8-1.2:

5.

5. The preparation method according to claim 1, characterized in that: Zn 2+ Source, In 3+ The source and sodium dodecyl sulfate are added to an ethylene glycol aqueous solution to obtain a mixed solution, thioacetamide is dispersed in the mixed solution, and a hydrothermal reaction is carried out at 110 to 130° C. to obtain an indium zinc sulfide catalyst.

6. The preparation method according to claim 5, characterized in that: The hydrothermal reaction time is 10 to 15 hours.

7. The preparation method according to claim 5, characterized in that: After the hydrothermal reaction is completed, a crude product is obtained. The crude product is washed by alternating centrifugation with deionized water and ethanol, and vacuum dried at 55-60° C. to obtain an indium zinc sulfide catalyst.

8. The preparation method according to claim 1, characterized in that: The Zn 2+ The source is zinc chloride or zinc nitrate, the In 3+ The source is indium chloride tetrahydrate.

9. An indium zinc sulfide catalyst prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the indium zinc sulfide catalyst according to claim 9 in photo-piezoelectric catalytic decomposition of water to produce hydrogen.

Images