Sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material with core-shell structure, preparation method and application
By growing the sulfur-containing vacancies on the NU-1000 nanorod to form a core-shell structure, the problem of photocatalytic activity limitation of Zn3In2S6 and NU-1000 materials is solved, and the effect of efficient production of H2 and H2O2 is achieved.
Patent Information
- Application Number
- CN202510299897.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2025-07-11
AI Technical Summary
The existing Zn3In2S6 photocatalysts have problems such as high probability of photogenerated carrier recombination, few surfactant sites and prone to agglomeration in the process of photocatalytic production of H2 and H2O2, which limits their photocatalytic activity; while the photogenerated carrier separation efficiency, poor conductivity and quantum yield of NU-1000 materials limits their industrial applications.
Zn3In2S6 nanoflowers containing sulfur vacancy were grown on the surface of NU-1000 nanorods by in-situ hydrothermal method to form a composite material with core-shell structures. The sulfur vacancy was used to accelerate electron delocalization, promote charge separation, and enhance charge transport and light absorption ranges through heterostructures.
It significantly improves the photocatalytic activity of composite materials, broadens the photoresponse range, increases the specific surface area and reactive sites, and achieves the ability to efficiently produce H2 and H2O2, and the catalytic activity is far better than that of monomer materials.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of inorganic-organic hybrid nanomaterials, and particularly relates to a core-shell structured sulfur-vacancy-containing Zn3In2S6 / NU-1000 composite material, a preparation method thereof, and an application thereof. Background Art
[0002] With the rapid development of social economy, the demand for traditional fossil energy is increasing day by day. From a long-term perspective, the development and utilization of green energy is an ideal choice for realizing the sustainable development of society. It is crucial to vigorously develop renewable energy to replace and accelerate the construction of a safe, efficient, clean and low-carbon energy strategy.
[0003] As a secondary energy source with high energy density, wide sources, and clean and pollution-free, H2 is considered to be one of the most ideal energy sources to replace fossil fuels and has now become an important starting point for the global low-carbon transformation of energy. However, the current H2 preparation methods mainly rely on fossil fuels and are not consistent with the policy of reducing carbon emissions. At the same time, as a green and widely used oxidant, H2O2 has only oxygen and water as the final products in oxidation reactions, will not cause secondary pollution to the environment and meet the requirements of green production, and has thus become one of the cleanest chemical raw materials. As a method capable of simultaneously producing H2 and H2O2, the photocatalytic oxidation-reduction technology has great application prospects. In the photocatalytic process, electrons are excited by sunlight to transfer, and thus oxidation-reduction reactions are carried out in the water environment to produce H2 and H2O2. However, current photocatalysts generally have defects such as a narrow visible light absorption range, low quantum efficiency, and low photogenerated charge separation efficiency. Therefore, the design and application of efficient catalytic materials are the key factors for promoting the industrialization of photocatalytic technology.
[0004] Zn3In2S6, as Zn m In2S 3+m(1 ≤ m ≤ 5) An important member of ternary metal sulfides, showing a hexagonal crystal phase structure. In the unit cell of Zn3In2S6, there are tetrahedral and octahedral interstitial sites. Zn atoms tend to occupy tetrahedral positions, while In atoms connect tetrahedra and octahedra. Moreover, the unit cell composed of the atomic sequence of S-In-S-Zn-S-In-S-Zn-S-Zn-S along the c-axis is divided by two consecutive sulfur layers, and there is a van der Waals gap between the two sulfur layers. The bandgap range of Zn3In2S6 is 2.5 - 2.8 eV, and the conduction band potential is approximately -0.8 eV, which enables it to meet the standard redox potential required for photocatalytic production of H2 and H2O2. However, single-component Zn3In2S6 is severely limited in its use for photocatalytic production of green energy due to the high probability of photogenerated carrier recombination, surface active sites, and easy agglomeration. Current research shows that modification of Zn3In2S6 can be achieved by impregnation with noble metals, defect engineering, and construction of heterojunctions with other semiconductor materials, which can broaden the light response range and improve its solar energy utilization rate. Compared with noble metal loading, finding a semiconductor material with a suitable bandgap to construct a heterojunction with it and implementing the defect engineering strategy together can greatly improve the inherent defects of Zn3In2S6, which is more economical and effective. Therefore, screening suitable semiconductor materials and determining specific strategies for defect construction are the keys to obtaining high photocatalytic activity.
[0005] NU-1000, a thermally stable Zr-based metal-organic framework material, has a macroporous structure and a wide visible light absorption range. The large voids and specific surface area of NU-1000 are very suitable for use as a support for catalysts or for constructing heterojunction photocatalysts by compounding with other materials. However, the low separation efficiency of photogenerated carriers, poor conductivity, and low quantum yield of NU-1000 materials limit their industrial applications. Summary of the Invention
[0006] Object of the Invention: Aiming at the problems existing in the prior art, the present invention provides a core-shell structure sulfur-vacancy-containing Zn3In2S6 / NU-1000 composite material, a preparation method and an application. First, NU-1000 nanorods are prepared by an oil bath method, then a dispersion of NU-1000 nanorods is prepared, and then the Zn3In2S6 precursor is added to the dispersion of NU-1000 nanorods respectively. A sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material is obtained by an in-situ hydrothermal method and used as a photocatalyst for producing H2 and H2O2 in water under visible light irradiation. The material prepared by the present invention has high visible light absorption performance and high photocatalytic activity.
[0007] Technical solution: In the first aspect, the present invention provides a method for preparing a sulfur-vacancy-containing Zn3In2S6 / NU-1000 composite material with a core-shell structure, comprising the following steps: S1. First, disperse benzoic acid in an N,N-dimethylformamide solution, stir, then add ZrCl4, ultrasonicate, and perform the first oil bath heating; cool, add 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene to the above reaction solution, ultrasonically disperse, maintain stirring and perform the second oil bath heating under reflux; cool, centrifuge to obtain a yellow precipitate; S2. After the yellow precipitate is first washed with N,N-dimethylformamide, place it in a mixed solution of N,N-dimethylformamide and hydrochloric acid, and perform oil bath heating under reflux; centrifuge to obtain a yellow-green precipitate; wash for the second time, dry, and perform heat treatment activation to obtain NU-1000 nanorods; S3. Place the NU-1000 nanorods in deionized water, ultrasonicate, then sequentially add ZnSO4·7H2O, In(NO3)3·4.5H2O and thioacetamide, stir, and perform hydrothermal reaction; cool, centrifuge, wash, and dry to obtain a sulfur-vacancy-containing Zn3In2S6 / NU-1000 composite material with a core-shell structure.
[0008] Further, in S1, the dosage ratio of benzoic acid, N,N-dimethylformamide, ZrCl4 and 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene is 72-310 mmol∶25-150 mL∶1-5 mmol∶0.25-1.25 mmol.
[0009] Further, in S1, the specific conditions for the first oil bath heating are: heating temperature is 60-80°C; heating time is 1-4 h; In S1, the specific conditions for the second oil bath heating are: heating temperature is 100-120°C; heating time is 10-16 h.
[0010] Further, in S2, in the mixed solution, the volume ratio of N,N-dimethylformamide to hydrochloric acid is 30-180 mL∶1-12 mL; wherein, the concentration of the hydrochloric acid is: 4-8 mol / L.
[0011] Further, in S2, the specific conditions for the oil bath heating are: heating temperature is 100-120°C; heating time is 10-16 h; In S2, the specific conditions for the heat treatment activation are: activation temperature is 100-120°C; activation time is 10-16 h.
[0012] Further, in S3, the dosage ratio of the NU-1000 nanorods, ZnSO4·7H2O, In(NO3)3·4.5H2O, thioacetamide and deionized water is 0.00478 - 0.54547 g∶0.75 - 15 mmol∶0.5 - 10 mmol∶1.5 - 30 mmol∶30 - 150 mL.
[0013] Further, in S3, the specific conditions of the hydrothermal reaction are as follows: the filling ratio of the hydrothermal reaction kettle is 40 - 60%; the reaction temperature is 140 - 180 °C; the reaction time is 8 - 24 h.
[0014] Preferably, in S2, the second washing is specifically: washing with N,N-dimethylformamide and dichloromethane multiple times.
[0015] In a second aspect, the present invention provides a sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material. The sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material is prepared according to the method described in any one of the above. The sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material is a core-shell structure with sulfur vacancy-containing Zn3In2S6 nanoflowers grown on NU-1000 nanorods; wherein, the mass ratio of NU-1000 in the sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material is 3 - 15%.
[0016] In a third aspect, the present invention provides an application of the sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material prepared according to the method described in any one of the above in producing H2 and H2O2 in water under visible light irradiation.
[0017] Theoretical Explanation: First, NU-1000 nanorods are prepared by solvothermal and heat treatment in the present invention. Then, the NU-1000 nanorods are dispersed in a Zn3In2S6 precursor solution, and a sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 composite material is obtained by regulating the sulfur source addition amount and in-situ hydrothermal growth method, and it is used for photocatalytic hydrogen production and hydrogen peroxide production. Innovatively, sulfur vacancies are introduced into Zn3In2S6 and allowed to grow on the NU-1000 nanorods in the present invention, enabling the uniform growth of sulfur-vacancy-containing Zn3In2S6 nanoflowers on the surface of NU-1000 nanorods to form a closely contacted core-shell structure: First, the introduction of sulfur vacancies can accelerate electron delocalization and prevent the recombination of electron-hole pairs, thereby improving the separation efficiency of carriers; Second, the heterostructure formed by Zn3In2S6 and NU-1000 promotes the directional transport of charges, and the photo-generated electrons are transported from NU1000 to sulfur-vacancy-containing Zn3In2S6; In addition, the tight core-shell structure reduces the aggregation of Zn3In2S6 nanoflowers, can increase the specific surface area of the composite material, improve the light absorption range, and promote the exposure of reactive sites, thereby promoting the improvement of catalytic activity. The present invention utilizes the synergistic effect between sulfur-vacancy-containing Zn3In2S6 and NU-1000 to promote the migration of photo-generated charges between the two-phase interfaces, expand the visible light absorption range, and improve the light absorption performance, thereby greatly improving the photocatalytic activity of the sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material, and having great industrial application prospects.
[0018] Advantages: Compared with the prior art, the specific advantages of the present invention are as follows: (1) The present invention first proposes a core-shell structured sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite structural material and also provides a preparation method for this novel composite structural material.
[0019] (2) The present invention first composites NU-1000 nanorods with sulfur-vacancy-containing Zn3In2S6 nanoflowers, effectively broadening the light response range of the composite material. The prepared sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite structural material has high visible light absorption performance and improves the utilization efficiency of sunlight.
[0020] (3) For the first time, the present invention uses an in-situ hydrothermal method to grow sulfur vacancy Zn3In2S6 nanoflowers on the surface of NU-1000 nanorods, which can achieve the uniform dispersion of sulfur vacancy Zn3In2S6 nanoflowers, greatly reduce the agglomeration phenomenon of Zn3In2S6, increase the active reaction sites and the specific surface area, and is conducive to the adsorption of reactant molecules on the surface of the composite structure material. At the same time, the in-situ grown core-shell structure can enable the two to form a tight interfacial contact, realize the effective separation of photogenerated electron-hole pairs, promote the efficient progress of redox reactions, and obtain excellent photocatalytic activity.
[0021] (4) The sulfur vacancy Zn3In2S6 nanoflower / NU-1000 nanorod composite catalytic material prepared by the present invention can be used as a catalyst for the production of H2 and H2O2 under visible light. Among them, when the mass ratio of NU-1000 nanorods in the composite structure material is 9%, after 4 h of visible light irradiation, the yield of H2 is 1,241.34 μM; for the production of H2O2, when irradiated with visible light for 2 h, the yield of H2O2 is 1,100.73 μM, and the catalytic activity of the composite material is far superior to that of the two monomers.
[0022] (5) The preparation process of the present invention is simple, the raw materials and the final products are both non-toxic and harmless, the reaction conditions are mild and easy to control, and the stability is good, and it has broad application prospects in the green production of fuels and chemical raw materials. Description of the Drawings Figure 1 It is the UV-VIS diagram of NU-1000 nanorods, sulfur vacancy Zn3In2S6 nanoflowers and different ratios of sulfur vacancy Zn3In2S6 / NU-1000 composite structure materials prepared in Examples 1, 3, and 5; Figure 2 It is the XRD diagram of NU-1000 nanorods, sulfur vacancy Zn3In2S6 nanoflowers and the sulfur vacancy Zn3In2S6 / NU-1000 composite structure material prepared in Example 2; Figure 3 It is the electron paramagnetic resonance test (EPR) diagram of the sulfur vacancy Zn3In2S6 / NU-1000 composite structure material prepared in Example 3; Figure 4 It is the cycle effect diagram of the photocatalytic production of H2 and H2O2 by the sulfur vacancy Zn3In2S6 / NU-1000 composite structure material prepared in Example 3 under visible light for four cycles; Figure 5 It is the SEM diagram of NU-1000 nanorods (a) and the sulfur vacancy Zn3In2S6 / NU-1000 composite structure material prepared in Example 4 (b). Detailed Embodiments
[0024] The present invention will be introduced in detail below in conjunction with the embodiments.
[0025] In the present invention, H2 and H2O2 are generated in water under visible light. A 300 W xenon lamp is used to simulate the solar light source, and a λ>420 nm filter is used to filter out the ultraviolet light region to evaluate the activity of the core-shell structured sulfur-vacancy-containing Zn3In2S6 nanoflowers / NU-1000 nanorod composite material prepared by the present invention in generating H2 and H2O2.
[0026] For the H2 generation experiment, the specific steps are as follows: Add 50 mL of deionized water to the photocatalytic reactor, then add 10 mL of triethanolamine as a sacrificial agent and 1.5 mL of 1 wt% chloroplatinic acid as a cocatalyst. Finally, add a certain mass of the sulfur-vacancy-containing Zn3In2S6 / NU-1000 composite material and disperse it fully by ultrasonic treatment. Under the condition of low-speed stirring, connect the sealed reaction vessel to the N2 channel and degas for 30 min. After the above steps are completed, turn on the xenon lamp for photocatalytic reaction. Use a syringe needle to extract 1 mL of the reaction gas every 1 h and inject it into the chromatographic column. Use a GC-9790 gas chromatograph to monitor the concentration of H2 produced, and select TCD as the chromatographic detector.
[0027] For the H2O2 generation experiment, the specific steps are as follows: After dispersing a certain mass of the sulfur-vacancy-containing Zn3In2S6 / NU-1000 composite material in 50 mL of deionized water fully by ultrasonic treatment, stir it for 30 min under dark conditions, and then turn on the xenon lamp for photocatalytic reaction. To determine the concentration of H2O2, color development is carried out by the iodometric method, and then the absorbance at the maximum absorption wavelength (λ Cr = 350 nm) is measured in a UV-visible spectrophotometer. The concentration of H2O2 is calculated based on the change in absorbance after illumination.
[0028] Example 1: This example provides a preparation method for a core-shell structured sulfur-vacancy-containing Zn3In2S6 / NU-1000 composite material, which is specifically as follows: First, weigh 72 mmol of benzoic acid and disperse it in 25 mL of N,N-dimethylformamide. After stirring for 10 - 30 min, weigh 1 mmol of ZrCl4 and add it to the above solution. Ultrasonic for 30 - 60 min, and then heat it at 60 °C for 4 h under oil bath conditions. After heating, remove the reaction vessel and wait for it to cool to room temperature. Add 0.25 mmol of 1,3,6,8-tetra(4-carboxyphenyl)pyrene to the above reaction solution, disperse it by ultrasonic treatment for 10 - 30 min, and then transfer it to a round-bottom flask. Keep stirring and heat it under oil bath at 100 °C for reflux for 16 h. After the reaction is completed, cool it naturally and centrifuge the yellow precipitate.
[0029] The yellow precipitate obtained finally in the above (1) was washed several times with N,N-dimethylformamide, and then added to a mixed solution of 30 mL of N,N-dimethylformamide and 1 mL of 8 mol / L hydrochloric acid, and heated under reflux in an oil bath at 100 °C for 16 h. After the reaction was completed, the yellow-green precipitate was separated by centrifugation, washed several times with N,N-dimethylformamide and dichloromethane, and then transferred to a vacuum drying oven to be dried to obtain NU-1000. Subsequently, it was placed in a crucible with a lid and transferred to an oven for heat treatment activation at 100 °C for 16 h to obtain NU-1000 nanorods.
[0030] Weigh 0.00478 g of the NU-1000 nanorods in (2) and put them into a beaker, add 30 mL of deionized water, and ultrasonicate for 10 - 30 min to disperse them evenly. Under stirring, add 0.75 mmol of ZnSO4·7H2O, 0.5 mmol of In(NO3)3·4.5H2O, and 1.5 mmol of thioacetamide (TAA) to the dispersion solution and stir well for 30 - 60 min to dissolve them. Then transfer the solution into a hydrothermal reaction kettle and heat it at 140 °C for 24 h. After the reaction is completed, cool it to room temperature, and after centrifugal washing with deionized water and absolute ethanol, dry it under vacuum to obtain a sulfur vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material. Among them, the mass ratio of NU-1000 nanorods in the composite catalyst accounts for 3%.
[0031] Figure 1 The figure in the middle is the solid ultraviolet-visible diffuse reflectance spectra of the sulfur vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material, sulfur vacancy-containing Zn3In2S6 nanoflower (Vs-Zn3In2S6), and NU-1000 prepared according to Example 1. It can be seen that the optical absorption edge of the sulfur vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material prepared in Example 1 has been improved well.
[0032] Take 50 mg each of NU-1000 nanorods, sulfur vacancy-containing Zn3In2S6 nanoflowers, and the sulfur vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material prepared according to Example 1. After visible light irradiation in 50 mL of pure water for 4 h, the yields of H2 are 4.16 μM, 206.81 μM, and 617.50 μM respectively; for the generation of H2O2, after visible light irradiation for 2 h, the generation rates of H2O2 of NU-1000 nanorods, sulfur vacancy-containing Zn3In2S6 nanoflowers, and the sulfur vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material prepared according to Example 1 are 14.31 μmol g -1 h -1, 121.37 μmol g -1 h -1 and 399.21 μmol g -1 h -1 。
[0033] Combined with the solid UV spectrum and the results of the activity test, it can be seen that the visible-light photocatalytic activity of the sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material prepared in Example 1 is significantly improved compared with that of the sulfur-vacancy Zn3In2S6 monomer and NU-1000.
[0034] Example 2: First, weigh 115.2 mmol of benzoic acid and disperse it in 40 mL of N,N-dimethylformamide. After stirring for 10 - 30 min, weigh 1.6 mmol of ZrCl4 and add it to the above solution. Ultrasonic for 30 - 60 min, and then heat it at 70 °C for 2 h under an oil bath condition. After heating, remove the reaction vessel and wait for it to cool to room temperature. Add 0.4 mmol of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene to the above reaction solution, ultrasonic disperse for 10 - 30 min, and then transfer it to a round-bottom flask. Keep stirring and heat it under an oil bath at 100 °C for reflux for 16 h. After the reaction is completed, cool it naturally and centrifuge the yellow precipitate.
[0035] After washing the yellow precipitate obtained in the above (1) with N,N-dimethylformamide multiple times, add it to a mixture of 45 mL of N,N-dimethylformamide and 1.5 mL of 8 mol / L hydrochloric acid, and heat it under an oil bath at 110 °C for reflux for 12 h. After the reaction is completed, centrifuge to separate the yellow-green precipitate, wash it with N,N-dimethylformamide and dichloromethane multiple times, and then transfer it to a vacuum drying oven to dry to obtain NU-1000. Subsequently, place it in a covered crucible and transfer it to an oven for heat treatment activation at 110 °C for 12 h to obtain NU-1000 nanorods.
[0036] Weigh 0.01973 g of the NU-1000 nanorods in (2) and put them into a beaker. Add 50 mL of deionized water and ultrasonic for 10 - 30 min to disperse them evenly. Under stirring, add 1.5 mmol of ZnSO4·7H2O, 1 mmol of In(NO3)3·4.5H2O and 3 mmol of thioacetamide (TAA) to the dispersion solution and stir well for 30 - 60 min to dissolve them. Transfer them to a hydrothermal reaction kettle and heat at 150 °C for 18 h. After the reaction is completed, cool it to room temperature. After centrifugal washing with deionized water and absolute ethanol, vacuum dry to obtain a sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite structural material, where the mass ratio of NU-1000 nanorods in the composite catalyst is 6%.
[0037] Figure 2 XRD test spectra of the sulfur vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite, NU-1000 nanorods, and sulfur vacancy-containing Zn3In2S6 nanoflowers prepared according to Example 2. It can be seen that the characteristic peaks of NU-1000 are contained in Example 2, and at the same time, it is basically consistent with the spectrum of sulfur vacancy-containing Zn3In2S6, indicating the successful composite of the two materials.
[0038] Take 50 mg each of NU-1000 nanorods, sulfur vacancy Zn3In2S6 nanoflowers, and the sulfur vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite prepared according to Example 2. After visible light irradiation for 4 h in 50 mL of pure water, the yield of H2 is 1067.18 μM; for the generation of H2O2, when 50 mg of the sulfur vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite prepared according to Example 2 is used and irradiated with visible light in pure water for 2 h, the yield of H2O2 is 740.52 μM.
[0039] Example 3: First, weigh 216 mmol of benzoic acid and disperse it in 90 mL of N,N-dimethylformamide. After stirring for 10 - 30 min, weigh 3 mmol of ZrCl4 and add it to the above solution. Ultrasonic for 30 - 60 min, and then heat at 70 °C for 2 h under oil bath conditions. After heating, remove the reaction vessel and wait for it to cool to room temperature. Add 0.75 mmol of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene to the above reaction solution, ultrasonic disperse for 10 - 30 min, and then transfer it to a round-bottom flask. Keep stirring and heat under reflux at 110 °C for 12 h. After the reaction is completed, naturally cool and centrifuge the yellow precipitate.
[0040] After washing the yellow precipitate obtained finally in (1) above with N,N-dimethylformamide multiple times, add it to a mixed solution of 90 mL of N,N-dimethylformamide and 4 mL of 6 mol / L hydrochloric acid, and heat under reflux at 120 °C for 10 h. After the reaction is completed, centrifuge to separate the yellow-green precipitate, wash it with N,N-dimethylformamide and dichloromethane multiple times, and transfer it to a vacuum drying oven to dry to obtain NU-1000. Then place it in a covered crucible and transfer it to an oven for heat treatment activation at 110 °C for 12 h to obtain NU-1000 nanorods.
[0041] Weigh 0.12228 g of the NU-1000 nanorods in (2) and put them into a beaker. Add 80 mL of deionized water and ultrasonicate for 10 - 30 min to disperse them evenly. Under stirring, add 6 mmol of ZnSO4·7H2O, 4 mmol of In(NO3)3·4.5H2O, and 12 mmol of thioacetamide (TAA) to the dispersed solution and stir well for 30 - 60 min to dissolve them. Transfer it into a hydrothermal reaction kettle and heat it at 160 °C for 12 h. After the reaction is completed, cool it to room temperature. After centrifugal washing with deionized water and absolute ethanol, dry it under vacuum to obtain a sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite structure material. Among them, the mass ratio of NU-1000 nanorods in the composite catalyst is 9%.
[0042] Figure 3 Figure 4 shows the electron paramagnetic resonance (EPR) test results of the sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material prepared according to Example 3, confirming the existence of sulfur vacancies in the composite material.
[0043] After irradiating 50 mg of the sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material prepared according to Example 3 with visible light in 50 mL of pure water for 4 h, the yield of H2 is 1241.34 μM; for the generation of H2O2, after irradiating 50 mg of the composite material prepared in Example 3 with visible light in 50 mL of pure water for 2 h, the yield of H2O2 is 1100.73 μM.
[0044] Figure 4 Figure 5 shows the efficiency diagram of H2 and H2O2 production by the sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material prepared according to Example 3 under visible light after four cycles. It can be seen from the figure that the activities of the sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material prepared according to Example 3 for H2 (98.1%) and H2O2 (95.4%) production can still maintain a relatively high activity after four cycles, indicating high stability and certain application value for long-term use.
[0045] Example 4: First, weigh 288 mmol of benzoic acid and disperse it in 120 mL of N,N-dimethylformamide. After stirring for 10 - 30 min, weigh 4 mmol of ZrCl4 and add it to the above solution. Ultrasonic for 30 - 60 min, and then heat it at 80 °C for 1 h under oil bath conditions. After heating, remove the reaction vessel and wait for it to cool to room temperature. Add 1 mmol of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene to the above reaction solution, ultrasonic disperse for 10 - 30 min, and then transfer it to a round-bottom flask. Keep stirring and heat it under oil bath at 110 °C for reflux for 12 h. After the reaction is completed, naturally cool and centrifuge the yellow precipitate.
[0046] The yellow precipitate obtained finally in the above (1) is washed several times with N,N-dimethylformamide, and then added to a mixed solution of 150 mL of N,N-dimethylformamide and 8 mL of 5 mol / L hydrochloric acid. Heat it under oil bath at 110 °C for reflux for 12 h. After the reaction is completed, centrifuge to separate the yellow-green precipitate, wash it several times with N,N-dimethylformamide and dichloromethane, and then transfer it to a vacuum drying oven to dry to obtain NU-1000. Subsequently, place it in a covered crucible and transfer it to an oven for heat treatment activation at 120 °C for 10 h to obtain NU-1000 nanorods.
[0047] Weigh 0.2529 g of the NU-1000 nanorods in (2) and put them into a beaker. Add 90 mL of deionized water and ultrasonic for 10 - 30 min to disperse them evenly. Under stirring conditions, add 12 mmol of ZnSO4·7H2O, 6 mmol of In(NO3)3·4.5H2O, and 18 mmol of thioacetamide (TAA) to the dispersed solution and stir well for 30 - 60 min to dissolve them. Transfer it to a hydrothermal reaction kettle and heat it at 170 °C for 10 h. After the reaction is completed, cool it to room temperature, and after centrifugal washing with deionized water and absolute ethanol, vacuum dry it to obtain a sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite structure material. Among them, the mass ratio of NU-1000 nanorods in the composite catalyst accounts for 12%.
[0048] Figure 5 Figure 10 is a scanning electron microscope image of NU-1000 (left) and sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite material (right) prepared according to Example 4. It can be seen from the figure the morphology of NU-1000 nanorods. In addition, in the sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite structure material prepared according to Example 4, Zn3In2S6 is in a nanoflower structure, and some nanoflowers have covered the NU-1000 nanorods.
[0049] Taking 50 mg of the sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite prepared in Example 4 and irradiating it with visible light in 50 mL of pure water for 4 h, the yield of H2 was 957.89 μM; for the generation of H2O2, taking 50 mg of the composite prepared in Example 4 and irradiating it with visible light in 50 mL of pure water for 2 h, the yield of H2O2 was 851.26 μM.
[0050] Example 5: First, weigh 310 mmol of benzoic acid and disperse it in 150 ml of N,N-dimethylformamide. After stirring for 10 - 30 min, weigh 5 mmol of ZrCl4 and add it to the above solution. Ultrasonic for 30 - 60 min, and then heat it at 80 °C in an oil bath for 1 h. After heating, remove the reaction vessel and wait for it to cool to room temperature. Add 1.25 mmol of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene to the above reaction solution, ultrasonic disperse for 10 - 30 min, and then transfer it to a round-bottom flask. Keep stirring and heat it under reflux at 120 °C in an oil bath for 10 h. After the reaction is completed, naturally cool and centrifuge the yellow precipitate.
[0051] After washing the yellow precipitate obtained finally in (1) above with N,N-dimethylformamide multiple times, add it to a mixture of 180 ml of N,N-dimethylformamide and 12 mL of 4 mol / L hydrochloric acid, and heat it under reflux at 120 °C in an oil bath for 10 h. After the reaction is completed, centrifuge to separate the yellow-green precipitate, wash it with N,N-dimethylformamide and dichloromethane multiple times, and transfer it to a vacuum drying oven to dry to obtain NU-1000. Then place it in a covered crucible and transfer it to an oven for heat treatment activation at 120 °C for 10 h to obtain NU-1000 nanorods.
[0052] Weigh 0.54547 g of the NU-1000 nanorods in (2) and put them into a beaker. Add 150 mL of deionized water and ultrasonic for 10 - 30 min to disperse them evenly. Under stirring, add 15 mmol of ZnSO4·7H2O, 10 mmol of In(NO3)3·4.5H2O and 30 mmol of thioacetamide (TAA) to the dispersion solution and stir well for 30 - 60 min to dissolve them. Transfer it to a hydrothermal reaction kettle and heat it at 180 °C for 8 h. After the reaction is completed, cool it to room temperature, and after centrifugal washing with deionized water and absolute ethanol, vacuum dry it to obtain a sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite structural material, where the mass ratio of NU-1000 nanorods in the composite catalyst accounts for 15%.
[0053] Taking 50 mg of the sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite prepared in Example 5 in 50 mL of pure water and irradiating it with visible light for 4 h, the yield of H2 was 733.17 μM. For the generation of H2O2, taking 50 mg of the sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite prepared in Example 5 and irradiating it with visible light for 2 h, the generation rate of H2O2 was 596.18 μmol g -1 h -1 。 Figure 1 Figure Figure 1 is the solid-state UV-visible diffuse reflectance spectra of the sulfur-vacancy-containing Zn3In2S6 nanoflower / NU-1000 nanorod composite prepared in Example 5 and two monomer materials. It can be seen from the figure that introducing sulfur-vacancy Zn3In2S6 nanoflowers onto NU-1000 nanorods has greatly improved the light absorption cut-off edge, thus greatly enhancing the photocatalytic activity.
[0054] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and it should not be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.
Claims
1. A preparation method of a core-shell structured sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material, characterized in that, It includes the following steps: S1. First, disperse benzoic acid in N,N-dimethylformamide solution, stir, then add ZrCl4, ultrasonicate, and perform the first oil bath heating; cool, add 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene to the above reaction solution, ultrasonically disperse, maintain stirring and perform the second oil bath heating under reflux; cool, centrifuge to obtain a yellow precipitate; S2. After the first washing of the yellow precipitate with N,N-dimethylformamide, place it in a mixed solution of N,N-dimethylformamide and hydrochloric acid, perform oil bath heating under reflux; centrifuge to obtain a yellow-green precipitate; wash for the second time, dry, and perform heat treatment activation to obtain NU-1000 nanorods; S3. Place the NU-1000 nanorods in deionized water, ultrasonicate, then sequentially add ZnSO4·7H2O, In(NO3)3·4.5H2O, and thioacetamide, stir, and perform a hydrothermal reaction; cool, centrifuge, wash, and dry to obtain a core-shell structured Zn3In2S6 / NU-1000 composite material containing sulfur vacancies.
2. The preparation method of the sulfur-vacancy-containing Zn3In2S6 / NU-1000 composite material according to claim 1, characterized in that: In S1, the dosage ratio of benzoic acid, N,N-dimethylformamide, ZrCl4, and 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene is 72 - 310 mmol∶25 - 150 mL∶1 - 5 mmol∶0.25 - 1.25 mmol.
3. The preparation method of the sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material according to claim 1, characterized in that: In S1, the specific conditions for the first oil bath heating are: heating temperature is 60 - 80 °C; heating time is 1 - 4 h; In S1, the specific conditions for the second oil bath heating are: heating temperature is 100 - 120 °C; heating time is 10 - 16 h.
4. The preparation method of the sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material according to claim 1, wherein: In S2, in the mixed solution, the volume ratio of N,N-dimethylformamide to hydrochloric acid is 30 - 180 mL∶1 - 12 mL; among them, the concentration of the hydrochloric acid is: 4 - 8 mol / L.
5. The preparation method of the sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material according to claim 1, wherein: In S2, the specific conditions for the oil bath heating are: heating temperature is 100 - 120 °C; heating time is 10 - 16 h; In S2, the specific conditions for the heat treatment activation are: activation temperature is 100 - 120 °C; activation time is 10 - 16 h.
6. The preparation method of the sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material according to claim 1, wherein: In S3, the dosage ratio of NU-1000 nanorods, ZnSO4·7H2O, In(NO3)3·4.5H2O, thioacetamide, and deionized water is 0.00478 - 0.54547 g∶0.75 - 15 mmol∶0.5 - 10 mmol∶1.5 - 30 mmol∶30 - 150 mL.
7. The preparation method of the sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material according to claim 1, characterized in that: In S3, the specific conditions for the hydrothermal reaction are: the filling ratio of the hydrothermal reaction kettle is 40 - 60%; the reaction temperature is 140 - 180 °C; the reaction time is 8 - 24 h.
8. The preparation method of the sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material according to any one of claims 1-7, characterized in that: In S2, the second washing is specifically: washing multiple times with N,N-dimethylformamide and dichloromethane.
9. A sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material, characterized in that: The sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material is prepared by the method according to any one of claims 1-8, and the sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material has a core-shell structure in which sulfur vacancy-containing Zn3In2S6 nanoflowers grow on NU-1000 nanorods; wherein, the mass ratio of NU-1000 in the sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material is 3-15%.
10. Application of a sulfur vacancy-containing Zn3In2S6 / NU-1000 composite material prepared by the method according to any one of claims 1-8 in producing H2 and H2O2 in water under visible light irradiation.