A W 18 O 49 / Zn 0.1 Cu 0.9 Preparation method and application of InS2 heterojunction photocatalyst

Abstract

The present application relates to a kind of W 18 O 49 / Zn 0.1 Cu 0.9 The application relates to a preparation method and application of an InS2 heterojunction photocatalyst, and belongs to the technical field of photocatalytic materials. 18 O 49 / Zn 0.1 Cu 0.9 The InS2 photocatalyst can be applied to the field of photocatalytic hydrogen evolution. 18 O 49 / Zn 0.1 Cu 0.9 In the InS2 photocatalyst prepared by the application, the doping of Zn can reduce the recombination of electron-hole pairs and improve the photoelectron injection efficiency. The construction of a heterojunction improves the separation efficiency of photo-generated carriers, significantly improves the light response ability of the material, and enhances the photocatalytic activity. The application is green and environmentally friendly, simple, easy to operate, and low in material preparation cost, in line with the current green and environmentally friendly concept, and has a wide application market prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photocatalytic materials, and particularly relates to a W 18 O 49 / Zn 0.1 Cu 0.9 InS2 heterojunction photocatalyst and a preparation method and application thereof. BACKGROUND

[0002] Photocatalytic hydrogen evolution is a technology for generating hydrogen by decomposing water using light energy. In recent years, it has attracted widespread attention due to its high efficiency and environmental protection. With the growth of global energy demand and the intensification of environmental problems, hydrogen is regarded as an important solution to replace fossil fuels. Compared with traditional hydrogen production methods, photocatalytic hydrogen evolution technology not only utilizes solar energy, a renewable resource, but also effectively solves problems such as large resource consumption and environmental pollution. This technology uses solar energy to catalyze water decomposition to produce hydrogen through semiconductor photocatalysts, providing a green solution to future energy crisis problems.

[0003] Copper indium sulfide (CuInS2) has appropriate electronic band structure, excellent light absorption capacity, environmental protection, stability and low cost, and is widely used in the field of visible light driven photocatalytic hydrogen evolution. However, single CuInS2 has a narrow band gap, high photo-generated carrier recombination efficiency, and low photocatalytic hydrogen production efficiency. Zn ion doping can improve the surface chemical state of CuInS2 and effectively enhance the photo-generated carrier density. 18 O 49 As a transition metal oxide, it has a high specific surface area and rich oxygen vacancies, and the band structure of CuInS2 and W 18 O 49 matches well. The application constructs a W 18 O 49 / Zn 0.1 Cu 0.9 InS2 heterojunction photocatalytic material, which can effectively suppress the recombination of photo-generated electrons and holes, thereby improving the photocatalytic activity. W 18 O 49 / Zn 0.1 Cu 0.9 InS2 heterojunction photocatalyst has not been reported for water decomposition to produce hydrogen. SUMMARY

[0004] The application provides a W 18 O 49 / Zn 0.1 Cu 0.9 InS2 heterojunction photocatalyst and a preparation method and application thereof to solve the problems in the prior art.

[0005] The technical scheme adopted by the present application is:

[0006] A W 18 O 49 / Zn 0.1 Cu 0.9 A preparation method of an InS2 heterojunction photocatalyst, comprising the following steps:

[0007] 1) InCl3, CuSO4.5H2O, NH2CSNH2 are sequentially added to a beaker containing N,N-dimethylformamide (DMF), and a magnetic stirrer is used for fully stirring until dissolved, then ZnCl2 is added to the above solution, stirring for 30 min, the obtained solution is transferred to an autoclave for hydrothermal reaction, after cooling to room temperature, the product is centrifuged, washed and dried in an oven to obtain Zn 0.1 Cu 0.9 InS2 photocatalytic material;

[0008] 2) WCl6 is dissolved in anhydrous ethanol, then Zn 0.1 Cu 0.9 InS2 is added and stirred, and then placed in an autoclave for hydrothermal reaction, after natural cooling, centrifugal washing and drying, W 18 O 49 / Zn 0.1 Cu 0.9 InS2 heterojunction photocatalyst.

[0009] Further, in the above preparation method, in step 1), the amounts of InCl3, CuSO4.5H2O, NH2CSNH2 and ZnCl2 are respectively 2 mmol, 1.8 mmol, 4.5 mmol and 0.2 mmol, and the amount of DMF is 60 mL.

[0010] Further, in the above preparation method, in step 1), the temperature of the hydrothermal reaction is 180℃, and the reaction time is 24 h.

[0011] Further, in the above preparation method, in step 2), the amount of anhydrous ethanol is 12 mL, the amount of WCl6 is 0.2 g, and the amount of Zn 0.1 Cu 0.9 InS2 is 0.05 g.

[0012] Further, in the above preparation method, in step 2), the temperature of the hydrothermal reaction is 160℃, and the reaction time is 6 h.

[0013] Further, in the above preparation method, in steps 1) and 2), the centrifugal washing is through washing twice with deionized water and three times with anhydrous ethanol, the centrifugal rotation speed is 8000 rpm, and the centrifugal time is 10 min each time.

[0014] Further, in the preparation method, the drying temperature in the step 1) and the step 2) is 60 DEG C.

[0015] The W 18 O 49 / Zn 0.1 Cu 0.9 Application of the InS2 heterojunction photocatalyst in decomposing water to produce hydrogen under light irradiation.

[0016] Further, in the application, the W 18 O 49 / Zn 0.1 Cu 0.9 The InS2 heterojunction photocatalyst is uniformly dispersed in a mixed solution of deionized water, triethanolamine and chloroplatinic acid, then the container containing the mixed solution is continuously ventilated with argon at 40 mL / min to discharge air and the reactor is sealed with a sample pad, and water is decomposed to produce hydrogen under light irradiation.

[0017] Further, in the application, the W 18 O 49 / Zn 0.1 Cu 0.9 The amount of the InS2 heterojunction photocatalyst is 20 mg, the amount of the deionized water is 18 mL, the amount of the triethanolamine is 2 mL, and the amount of the chloroplatinic acid is 20 muL.

[0018] The present application has the following beneficial effects:

[0019] 1. The present application uses a two-step hydrothermal method to prepare a W 18 O 49 / Zn 0.1 Cu 0.9 InS2 heterojunction photocatalyst, and the doping of Zn can reduce the recombination of electron-hole pairs and improve the photoelectron injection efficiency.

[0020] 2. The W 18 O 49 / Zn 0.1 Cu 0.9 InS2 heterojunction photocatalyst prepared by the present application has improved separation efficiency of photo-generated carriers, significantly improved light response ability of the material, and enhanced photocatalytic activity.

[0021] 3. The W 18 O 49 / Zn 0.1 Cu 0.9The InS2 heterojunction photocatalyst has good photocatalytic hydrogen evolution performance, and the method is simple, convenient, low-cost, mild in conditions and conducive to large-scale production. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 CuInS2 catalyst prepared in Example 1, Zn 0.1 Cu 0.9 InS2 catalyst prepared in Example 2, W 18 O 49 catalyst prepared in Example 3, W 18 O 49 / CuInS2 catalyst and W 18 O 49 / Zn 0.1 Cu 0.9 X-ray 2θ = 10°-80° diffraction pattern of the InS2 heterojunction photocatalyst.

[0023] Figure 2 CuInS2 catalyst prepared in Example 1, Zn 0.1 Cu 0.9 InS2 catalyst prepared in Example 2, W 18 O 49 / CuInS2 catalyst and W 18 O 49 / Zn 0.1 Cu 0.9 X-ray 2θ = 27.5°-28.5° diffraction pattern of the InS2 heterojunction photocatalyst.

[0024] Figure 3 CuInS2 catalyst prepared in Example 1, Zn 0.1 Cu 0.9 InS2 catalyst prepared in Example 2, W 18 O 49 catalyst prepared in Example 3, W 18 O 49 / CuInS2 catalyst and W 18 O 49 / Zn 0.1 Cu 0.9 Photocatalytic hydrogen evolution activity diagram of the InS2 heterojunction photocatalyst.

[0025] Figure 4 CuInS2 catalyst prepared in Example 1, Zn 0.1 Cu 0.9 InS2 catalyst prepared in Example 2, W 18 O49 Catalyst, W prepared in Example 4 18 O 49 / CuInS2catalyst and W of Example 5 18 O 49 / Zn 0.1 Cu 0.9 Photoluminescence spectrum (PL) of InS2heterojunction photocatalyst. DETAILED DESCRIPTION

[0026] Example 1

[0027] The preparation method of CuInS2catalyst is as follows:

[0028] 2mmol of InCl3, 2mmol of CuSO4·5H2O, and 4.5mmol of NH2CSNH2 were placed in a beaker containing 60mL of DMF and stirred by a magnetic stirrer for 30min, then transferred to a 75mL autoclave for hydrothermal reaction at 180℃ for 24h. After cooling to room temperature, centrifugal washing was performed at a speed of 8000rpm, and deionized water was used for washing twice and anhydrous ethanol was used for washing three times, with each centrifugal time being 10min. After drying at 60℃, the CuInS2photocatalyst was obtained by grinding.

[0029] Example 2

[0030] Zn 0.1 Cu 0.9 The preparation method of InS2catalyst is as follows:

[0031] 2mmol of InCl3, 1.8mmol of CuSO4·5H2O, and 4.5mmol of NH2CSNH2 were placed in a beaker containing 60mL of DMF and stirred uniformly, then 0.2mmol of ZnCl2 was added and stirred for 30min, then transferred to a 75mL autoclave for hydrothermal reaction at 180℃ for 24h. After cooling to room temperature, centrifugal washing was performed at a speed of 8000rpm, and deionized water was used for washing twice and anhydrous ethanol was used for washing three times, with each centrifugal time being 10min. After drying at 60℃, the Zn 0.1 Cu 0.9 InS2photocatalyst.

[0032] Example 3

[0033] W 18 O 49 The preparation method of catalyst is as follows:

[0034] WCl6, 0.2 g, was placed in a beaker containing 12 mL of ethanol, stirred by a magnetic stirrer for 20 min, transferred to a 15 mL autoclave for hydrothermal reaction at 160 °C for 6 h, centrifuged and washed after cooling to room temperature at a speed of 8000 rpm, washed twice with deionized water and three times with absolute ethanol, each time for 10 min, and grinded after drying to obtain W 18 O 49 photocatalyst.

[0035] Example 4

[0036] W 18 O 49 The preparation method of the / CuInS2 photocatalyst is as follows:

[0037] WCl6, 0.2 g, was placed in a beaker containing 12 mL of ethanol, added with CuInS2 prepared in Example 1, 0.05 g, stirred by a magnetic stirrer for 20 min, transferred to a 15 mL autoclave for hydrothermal reaction at 160 °C for 6 h, centrifuged and washed after cooling to room temperature at a speed of 8000 rpm, washed twice with deionized water and three times with absolute ethanol, each time for 10 min, and grinded after drying to obtain W 18 O 49 / CuInS2 photocatalyst.

[0038] Example 5

[0039] W 18 O 49 / Zn 0.1 Cu 0.9 InS2 photocatalyst.

[0040] WCl6, 0.2 g, was placed in a beaker containing 12 mL of ethanol, added with Zn 0.1 Cu 0.9 InS2 prepared in Example 2, 0.05 g, stirred by a magnetic stirrer for 20 min, transferred to a 15 mL autoclave for hydrothermal reaction at 160 °C for 6 h, centrifuged and washed after cooling to room temperature at a speed of 8000 rpm, washed twice with deionized water and three times with absolute ethanol, each time for 10 min, and grinded after drying to obtain W 18 O 49 / Zn 0.1 Cu 0.9 InS2 photocatalyst.

[0041] Figure 1 The CuInS2 photocatalyst prepared in Example 1, the Zn 0.1 Cu 0.9 InS2 photocatalyst prepared in Example 2, the W 18 O49 Catalyst, W prepared in Example 4 18 O 49 Catalyst, W prepared in Example 4 18 O 49 Catalyst, W prepared in Example 4 0.1 Cu 0.9 X-ray 2-theta = 10°-80° diffraction pattern of the CuInS2 heterojunction photocatalyst. Figure 1 characteristic diffraction peaks at 2-theta = 27.9° and 46.5° corresponding to the (1 1 2) and (2 0 4) planes of chalcopyrite structured CuInS2 (JCPDS NO. 85-1575), W 18 O 49 characteristic peaks corresponding to the monoclinic structured W 18 O 49 (JCPDS NO. 72-0478) were observed. The characteristic peaks of CuInS2 and W 18 O 49 were observed in all the composite samples, indicating the successful preparation of W 18 O 49 / CuInS2 heterojunction photocatalyst. Figure 2 Catalyst, Zn 0.1 Cu 0.9 Catalyst, W prepared in Example 4 18 O 49 Catalyst, W prepared in Example 4 18 O 49 Catalyst, W prepared in Example 4 0.1 Cu 0.9 X-ray 2-theta = 27.5°-28.5° diffraction pattern of the CuInS2 heterojunction photocatalyst. The strongest diffraction peak of CuInS2 shifted to a larger angle after the introduction of Zn, confirming the successful doping of Zn ions. Figure 1 together with the results Figure 2 indicated the successful preparation of W 18 O 49 Catalyst, W prepared in Example 4 0.1 Cu 0.9 Catalyst, W prepared in Example 4

[0042] Example 6

[0043] W 18 O 49 Catalyst, W prepared in Example 4 0.1 Cu 0.9 Application of the CuInS2 heterojunction photocatalyst in the photocatalytic decomposition of water to produce hydrogen under light irradiation:

[0044] 1) Under normal temperature and pressure, 20 mg of W 18 O 49 / Zn 0.1 Cu 0.9 InS2heterojunction photocatalyst was placed in a reactor containing a mixture of 18 mL of deionized water, 2 mL of triethanolamine and 20 μL of chloroplatinic acid; argon was bubbled into the reactor at a rate of 40 mL / min for 20 min to remove air; under visible light irradiation, 1000 μL of gas in the reactor was withdrawn every 20 min, and the collected catalytic products were quantitatively analyzed using a gas chromatograph.

[0045] 2) The operation was carried out according to step 1), except that 20 mg of W 18 O 49 / Zn 0.1 Cu 0.9 InS2heterojunction photocatalyst was replaced by CuInS2catalyst prepared in Example 1, Zn 0.1 Cu 0.9 InS2catalyst prepared in Example 2, W 18 O 49 catalyst prepared in Example 3, and W 18 O 49 / CuInS2catalyst prepared in Example 4, respectively, and the hydrogen production efficiency was determined.

[0046] Figure 3 The hydrogen content versus light irradiation time is shown in the graph, and the peak area of the extracted gas was measured by a gas chromatograph, and then converted into the amount of substance by calculation, as shown in the following formula: Figure 3 After 2 h, the H2production of CuInS2catalyst was 149.21 μmol / g, the H2production of W 18 O 49 catalyst was 6.66 μmol / g, and the activity of both was low; the H2production of Zn 0.1 Cu 0.9 InS2catalyst was 209.04 μmol / g, the H2production of W 18 O 49 / CuInS2catalyst was 282.04 μmol / g, the H2production of W 18 O 49 / Zn 0.1 Cu 0.9 InS2heterojunction photocatalyst was 368.46 μmol / g, which was higher than that of CuInS2catalyst and W 18 O 49 catalyst, indicating that ion doping and construction of heterojunction have strong redox ability.

[0047] Figure 4 CuInS2catalyst prepared for Example 1, Zn 0.1 Cu 0.9 InS2catalyst prepared for Example 2, W 18 O 49 catalyst prepared for Example 3, W 18 O 49 / CuInS2catalyst and W 18 O 49 / Zn 0.1 Cu 0.9 PL spectra of the InS2heterojunction photocatalysts. W 18 O 49 CuInS2also had a relatively high emission intensity. Compared to W 18 O 49 All the remaining samples showed lower emission intensity compared to Zn-doped and CuInS2, confirming that Zn-doping and the construction of heterojunctions effectively reduced the carrier transport resistance and reduced charge recombination.

Claims

1. A type of W 18 O 49 / Zn 0.1 Cu 0.9 The method for preparing InS2 heterojunction photocatalysts is characterized by, Includes the following steps: 1) InCl3, CuSO4·5H2O, and NH2CSNH2 were sequentially added to a beaker containing DMF. The mixture was stirred thoroughly with a magnetic stirrer until dissolved. ZnCl2 was then added to the solution, and the mixture was stirred for 30 minutes. The resulting solution was transferred to an autoclave for hydrothermal reaction. After cooling to room temperature, the product was centrifuged, washed, and dried in an oven to obtain ZnCl2. 0.1 Cu 0.9 InS2 photocatalytic materials; 2) Dissolve WCl6 in anhydrous ethanol, then add Zn 0.1 Cu 0.9 InS2, stir, and place in an autoclave for hydrothermal reaction. After natural cooling, centrifuge, wash, and dry to obtain W. 18 O 49 / Zn 0.1 Cu 0.9 InS2 heterojunction photocatalyst.

2. The preparation method according to claim 1, characterized in that, In step 1), the amounts of InCl3, CuSO4·5H2O, NH2CSNH2, and ZnCl2 used are 2 mmol, 1.8 mmol, 4.5 mmol, and 0.2 mmol, respectively, and the amount of DMF used is 60 mL.

3. The preparation method according to claim 1, characterized in that, In step 1), the hydrothermal reaction temperature is 180°C and the reaction time is 24 hours.

4. The preparation method according to claim 1, characterized in that, In step 2), the amount of anhydrous ethanol used is 12 mL, the amount of WCl6 used is 0.2 g, and the amount of Zn is... 0.1 Cu 0.9 The dosage of InS2 is 0.05g.

5. The preparation method according to claim 1, characterized in that, In step 2), the hydrothermal reaction temperature is 160°C and the reaction time is 6 hours.

6. The preparation method according to claim 1, characterized in that, In steps 1) and 2), the centrifugal washing involves washing twice with deionized water and three times with anhydrous ethanol, with a centrifugation speed of 8000 rpm and a centrifugation time of 10 min each time.

7. The preparation method according to claim 1, characterized in that, In steps 1) and 2), the drying temperature is 60°C.

8. W prepared by the method according to any one of claims 1-7 18 O 49 / Zn 0.1 Cu 0.9 Application of InS2 heterojunction photocatalyst in water splitting for hydrogen production under light irradiation.

9. The application according to claim 8, characterized in that, The method is as follows: Take W 18 O 49 / Zn 0.1 Cu 0.9 The InS2 heterojunction photocatalyst was uniformly dispersed in a mixed solution of deionized water, triethanolamine and chloroplatinic acid. Argon gas was continuously introduced into the container containing the mixed solution at a rate of 40 mL / min to purge air, and the reactor was sealed with a sample inlet pad. Hydrogen was produced by water decomposition under light irradiation.

10. The application according to claim 9, characterized in that, The W 18 O 49 / Zn 0.1 Cu 0.9 The amount of InS2 heterojunction photocatalyst used was 20 mg, the amount of deionized water was 18 mL, the amount of triethanolamine was 2 mL, and the amount of chloroplatinic acid was 20 μL.

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