Ionic liquid assisted defective znin2s4 photocatalyst and preparation method and application thereof

Abstract

The application discloses an ionic liquid synergistic defect ZnIn2S4 photocatalyst, a preparation method and application, and relates to the technical field of photocatalysts. Zn The ionic liquid synergistic defect ZnIn2S4 photocatalyst comprises a V Zn -ZIS carrier and ionic liquid dispersed on the V Zn -ZIS carrier; the V Zn -ZIS carrier is ZnIn2S4 containing Zn vacancies, and electronic transfer exists between the V Zn -ZIS carrier and the ionic liquid; the application prepares V Zn -ZIS / ionic liquid by a simple in-situ adding method, promotes electronic transfer between the V Zn -ZIS carrier and the ionic liquid by introducing Zn vacancies, thereby adjusting the electronic state of active sites and improving photocatalytic performance. Test results under a diluted CO2 condition show that the introduction of the ionic liquid can enrich CO2, thereby improving the yield of CO.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photocatalysts, in particular to a kind of ionic liquid cooperates with defect ZnIn2S4 Photocatalyst and preparation method and application. BACKGROUND

[0002] Photocatalysis technology provides a green and sustainable way for CO2 conversion due to its unique advantage of utilizing solar energy to drive chemical reactions. Among them, photocatalytic reduction of CO2 to syngas (main components are carbon monoxide and hydrogen) has important practical significance. Syngas is an important fuel and chemical intermediate, which can be further converted into liquid fuels, methanol and other chemicals through Fischer-Tropsch synthesis process, and has a wide application in energy and chemical industry

[0003] Among the numerous photocatalysts, ZnIn2S4 (ZIS) as a typical layered ternary metal sulfide, has attracted widespread attention in the field of photocatalytic CO2 reduction due to its suitable energy band structure (band gap of about 2.3 eV-2.4 eV), good visible light absorption performance and chemical stability.

[0004] In order to improve the photocatalytic performance of ZIS, researchers have carried out a lot of work. Defect engineering is one of the common modification strategies. By introducing defects (such as Zn vacancies, In vacancies, etc.) in the crystal structure of ZIS, its electronic structure can be adjusted, the adsorption and activation ability of CO2 can be enhanced, and the separation and transfer of photo-generated charges can be promoted. For example, by introducing Zn vacancies on the surface of ZIS through hydrothermal method, the activity of photocatalytic CO2 reduction to CO can be significantly improved.

[0005] However, the existing photocatalysts still have the problems of low catalytic activity and difficulty in capturing CO2. Therefore, how to further improve the catalytic activity of photocatalysts is a problem to be solved. SUMMARY

[0006] The present application aims to at least solve one of the technical problems existing in the prior art, and provides a kind of ionic liquid cooperates with defect ZnIn2S4 Photocatalyst and preparation method and application.

[0007] As a new type of green solvent, ionic liquid has the characteristics of low vapor pressure, high chemical stability and high CO2 solubility, and shows good application prospect in photocatalytic CO2 reduction system. The introduction of ionic liquid into photocatalytic system not only can improve the concentration of CO2, but also can optimize the reaction interface environment and inhibit the occurrence of side reactions. Therefore, the present application combines ionic liquid with defect ZnIn2S4 photocatalyst for CO2 photocatalytic reduction, and achieves certain effect.

[0008] The application forms a composite photocatalyst by synthesizing ZIS with Zn vacancies first, and then using the method of electrostatic assembly to form the composite photocatalyst through the interaction between the host and the guest between the Zn vacancy ZIS and the ionic liquid. There is a synergistic effect between the ZIS and the ionic liquid, and the introduction of the Zn vacancy significantly enhances the synergistic catalysis of the photocatalyst and the ionic liquid, thereby improving the catalytic performance of the photocatalyst.

[0009] The technical solution of the application is as follows:

[0010] The first aspect of the application provides an ionic liquid synergistic defect ZnIn2S4 photocatalyst, the ionic liquid synergistic defect ZnIn2S4 photocatalyst comprising V Zn -ZIS carrier and ionic liquid dispersed in the V Zn -ZIS carrier.

[0011] The V Zn -ZIS carrier is ZnIn2S4 containing Zn vacancies, and the V Zn -ZIS carrier and the ionic liquid have electron transfer therebetween.

[0012] Optionally, the ionic liquid is dispersed in the Zn vacancies in the V Zn -ZIS carrier.

[0013] Optionally, the V Zn -ZIS carrier is in a nanoflower structure.

[0014] Optionally, the ionic liquid comprises at least one of [Bmim]PF6, [EMIm]NTF2, [EMIm]Br, BMIC, [Emim]BF4, [Emim][OAc], [EMIM]PF6.

[0015] Optionally, the ratio of the V Zn -ZIS carrier to the ionic liquid is 20 mg: 50 μL~1000 μL. Preferably, the ratio of the V Zn -ZIS carrier to the ionic liquid is 20 mg: 50 μL~300 μL; more preferably, the ratio of the V Zn -ZIS carrier to the ionic liquid is 20 mg: 100 μL.

[0016] Optionally, the V Zn -ZIS carrier comprises the following steps:

[0017] 0.4 mmol of ZnCl2, 0.8 mmol of InCl3·4H2O and 3.2 mmol of thioacetamide are dissolved in 15 mL of ethanol and 15 mL of H2O to obtain a mixture;

[0018] The mixture was transferred to a reaction kettle, sealed, heated at 453 K for 24 h, after natural cooling to room temperature, the supernatant was sucked, the obtained gray-yellow product was collected by centrifugation, washed, dried, and V was obtained Zn -ZIS carrier.

[0019] The second aspect of the present application provides a preparation method of an ionic liquid synergistic defect ZnIn2S4 photocatalyst, which comprises the following steps:

[0020] S1, preparing V Zn -ZIS carrier;

[0021] S2, dispersing ionic liquid on the V Zn -ZIS carrier by in-situ adding method to obtain an ionic liquid synergistic defect ZnIn2S4 photocatalyst.

[0022] Optionally, S2 comprises the following specific steps:

[0023] V Zn -ZIS carrier, acetonitrile, TEOA and ionic liquid were added into a container, mixed uniformly, dried, and an ionic liquid synergistic defect ZnIn2S4 photocatalyst was obtained.

[0024] Optionally, V Zn -ZIS carrier, acetonitrile, TEOA and ionic liquid are added in a ratio of 20 mg:45 mL:5 mL:50 μL~1000 μL.

[0025] Optionally, a preparation method of an ionic liquid synergistic defect ZnIn2S4 photocatalyst comprises the following specific steps:

[0026] (1) A three-dimensional hierarchical ZnIn2S4 photocatalyst with zinc-rich vacancies was synthesized by a hydrothermal method. 0.4 mmol (0.05 g) of ZnCl2, 0.8 mmol (0.23 g) of InCl3·4H2O and 3.2 mmol (0.24 g) of thioacetamide were dissolved in 15 mL of ethanol and 15 mL of H2O, and ultrasonic treatment was performed for 5 min. The mixture was transferred to a teflon-lined high-pressure reaction kettle (capacity of 50 mL), sealed. It was heated at 453 K for 24 h, and after natural cooling to room temperature, the supernatant was sucked with a plastic pipette, and the obtained gray-yellow product was collected by centrifugation, washed with H2O and ethanol for 3 times respectively. The product was dried in an oven at 353 K for one night.

[0027] (2) 20 mg of ZnIn2S4 photocatalyst, 45 mL of acetonitrile and 5 mL of TEOA were added into a multifunctional photochemical reactor, and [Bmim]PF6 was added in situ. Meanwhile, the optimal ratio of adding [Bmim]PF6 was studied, including 50 μL, 100 μL, 200 μL, 300 μL, 1000 μL, and recorded as V Zn -ZIS / [Bmim]PF6-X. Wherein X = 50 μL, 100 μL, 200 μL, 300 μL and 1000 μL.

[0028] The third aspect of the present application provides an application of an ionic liquid synergistic defect ZnIn2S4 photocatalyst in photocatalytic CO2 reduction to produce synthesis gas.

[0029] Optionally, the V Zn -ZIS / [Bmim]PF6-100 photocatalyst was used to produce synthesis gas by photocatalytic CO2 reduction under AM1.5G light irradiation, and the temperature was 298 K.

[0030] The present application has at least one of the following beneficial effects:

[0031] (1) The present application prepares V Zn -ZIS by a simple and environmentally friendly hydrothermal method, and ionic liquid such as [Bmim]PF6 is used as a carrier, and the ionic liquid is highly dispersed on the V Zn -ZIS nanoflower by a simple in-situ addition method, and V Zn -ZIS / [Bmim]PF6 is prepared. This method promotes the electron transfer between the carrier V Zn -ZIS and the ionic liquid [Bmim]PF6 by introducing Zn vacancies, so as to adjust the electronic state of the active site and improve the photocatalytic performance. The test results under the condition of dilute CO2 (15%) show that the introduction of ionic liquid can enrich CO2, thereby significantly improving the yield of CO.

[0032] (2) The V Zn -ZIS / [Bmim]PF6 photocatalyst prepared by the present application has excellent activity, which is attributed to the synergistic effect of Zn vacancies and ionic liquid. The mapping results of TEM show that the introduction of Zn vacancies enables the photocatalyst to load more ionic liquid. The catalytic experiment also proves that the introduction of Zn vacancies significantly enhances the synergistic catalysis of the photocatalyst and the ionic liquid, and the defect-free sample and the ionic liquid cannot realize synergistic catalysis.

[0033] (3) The V ZnThe ZIS / [Bmim]PF6 photocatalyst has excellent photocatalytic performance, and the total yield of synthesis gas is 33.565 mmol g -1 h -1 The yield of H2 is 33.412 mmol g -1 h -1 The yield of CO is 153.508 μmol g -1 h -1 The stability test also proves that the sample has good durability.

[0034] (4) The photocatalyst provided by the application has the advantages of high efficiency, stability and low preparation cost, and the catalyst provides a new idea for the synergistic effect of defect engineering and ionic liquid. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The V-ZIS / [Bmim]PF6-100 photocatalyst prepared in Example 1 of the application is shown. Zn The ZIS / [Bmim]PF6-100, ZIS and V-ZIS prepared in Comparative Example 1-Comparative Example 3 are shown. Zn The X-ray diffraction pattern of ZIS is shown.

[0036] Figure 2 The V-ZIS / [Bmim]PF6-100 photocatalyst prepared in Example 1 of the application is shown. Zn The ZIS / [Bmim]PF6-100, ZIS and V-ZIS prepared in Comparative Example 1-Comparative Example 3 are shown. Zn The Fourier transform infrared spectrum of ZIS is shown.

[0037] Figure 3 The V-ZIS photocatalyst prepared in Comparative Example 3 of the application is shown. Zn The Zeta potential diagram of the V-ZIS photocatalyst and [Bmim]PF6 in Comparative Example 4 is shown.

[0038] Figure 4 The V-ZIS / [Bmim]PF6-100 photocatalyst prepared in Example 1 of the application is shown. Zn The V-ZIS photocatalyst prepared in Comparative Example 3 of the application is shown. Zn The electron paramagnetic resonance test diagram of ZIS is shown.

[0039] Figure 5 The V-ZIS / [Bmim]PF6-100 photocatalyst prepared in Example 1 of the application is shown. Zn The V-ZIS photocatalyst prepared in Comparative Example 3 of the application is shown. Zn The X-ray photoelectron spectrogram of ZIS is shown.

[0040] Figure 6 The V-ZIS / [Bmim]PF6-100 photocatalyst prepared in Example 1 of the application is shown.Zn Field emission scanning electron microscope (FESEM) image (a) and transmission electron microscope (TEM) image (b) of ZIS / [Bmim]PF6-100 photocatalyst, and V photocatalyst prepared in Comparative Example 3 Zn Transmission electron microscope (TEM) image (c) and energy dispersive spectroscopy (EDS) image (d) of ZIS;

[0041] Figure 7 V photocatalyst prepared in Example 1 of the present application Zn Performance test chart of ZIS / [Bmim]PF6-100 photocatalyst for 5 hours of photocatalytic production of synthesis gas

[0042] Figure 8 V photocatalyst prepared in Example 1 of the present application Zn ZIS / [Bmim]PF6-100 photocatalyst and ZIS / [Bmim]PF6-100, ZIS and V photocatalysts prepared in Comparative Example 1, Comparative Example 2 and Comparative Example 3, respectively Zn Performance test chart of ZIS photocatalyst for photocatalytic production of synthesis gas

[0043] Figure 9 V photocatalyst prepared in Example 1 of the present application Zn ZIS / [Bmim]PF6-100 photocatalyst and V photocatalysts prepared in Example 2 to Example 5 Zn ZIS / [Bmim]PF6-50, V Zn ZIS / [Bmim]PF6-200, V Zn ZIS / [Bmim]PF6-300, V Zn Performance test chart of ZIS / [Bmim]PF6-100 photocatalyst for photocatalytic production of synthesis gas

[0044] Figure 10 V photocatalyst prepared in Example 1 of the present application Zn Performance test chart of ZIS / [Bmim]PF6-100 photocatalyst for 12 hours of photocatalytic production of synthesis gas

[0045] Figure 11 V photocatalyst prepared in Example 1 of the present application Zn ZIS / [Bmim]PF6-100 photocatalyst and ZIS / [Bmim]PF6-100, ZIS and V photocatalysts prepared in Comparative Example 1 to Comparative Example 3 Zn Performance test chart of ZIS photocatalyst for photocatalytic production of synthesis gas under 15% CO2 condition. DETAILED DESCRIPTION

[0046] In order to make the technical problems, technical solutions and beneficial effects solved by the present application more clearly understood, the present application will be further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0047] Example 1

[0048] V Zn A preparation method of the ZIS / [Bmim]PF6-100 photocatalyst, which specifically comprises the following steps:

[0049] (1) V Zn A preparation method of the ZIS photocatalyst

[0050] A three-dimensional hierarchical ZnIn2S4 with rich zinc vacancies was synthesized by a hydrothermal method. 0.4 mmol (0.05 g) of ZnCl2, 0.8 mmol (0.23 g) of InCl3·4H2O and 3.2 mmol (0.24 g) of thioacetamide were dissolved in 15 mL of ethanol and 15 mL of H2O, and the mixture was subjected to ultrasonic treatment for 5 min. The mixture was transferred into a polytetrafluoroethylene-lined high-pressure reaction kettle (with a capacity of 50 mL) and sealed. The mixture was heated at 453 K for 24 h, and then naturally cooled to room temperature. The supernatant was sucked by a plastic pipette, and the obtained grayish yellow product was collected by centrifugation and washed with H2O and ethanol for 3 times, respectively. The product was dried in an oven at 353 K for one night to obtain V Zn -ZIS photocatalyst.

[0051] (2) V Zn Preparation of the ZIS / [Bmim]PF6-100 photocatalyst

[0052] 20 mg of the V Zn -ZIS photocatalyst prepared in step (1) and 50 mL of acetonitrile were added into a beaker, and 100 μL of [Bmim]PF6 was added in situ. The mixture was stirred for 30 min, and then transferred into a blast drying oven and dried at 80 ℃ overnight to obtain V Zn -ZIS / [Bmim]PF6-100.

[0053] Example 2

[0054] A V Zn -ZIS / [Bmim]PF6-50 photocatalyst was prepared by a method similar to that in Example 1, except that the amount of [Bmim]PF6 added in step (2) in Example 1 was changed to 50 μL, and the other steps were completely the same, to obtain V Zn -ZIS / [Bmim]PF6-50 photocatalyst.

[0055] Example 3

[0056] A V Zn The preparation method of ZIS / [Bmim]PF6-200 photocatalyst is similar to the method in Example 1, the only difference is that the amount of [Bmim]PF6 added in step (2) of Example 1 is changed to 200 μL, and the other steps are completely the same, and V is obtained. Zn ZIS / [Bmim]PF6-200 photocatalyst.

[0057] Example 4

[0058] A V Zn The preparation method of ZIS / [Bmim]PF6-300 photocatalyst is similar to the method in Example 1, the only difference is that the amount of [Bmim]PF6 added in step (2) of Example 1 is changed to 300 μL, and the other steps are completely the same, and V is obtained. Zn ZIS / [Bmim]PF6-300 photocatalyst.

[0059] Example 5

[0060] A V Zn The preparation method of ZIS / [Bmim]PF6-1000 photocatalyst is similar to the method in Example 1, the only difference is that the amount of [Bmim]PF6 added in step (2) of Example 1 is changed to 1000 μL, and the other steps are completely the same, and V is obtained. Zn ZIS / [Bmim]PF6-1000 photocatalyst.

[0061] Comparative Example 1

[0062] The preparation method of ZIS / [Bmim]PF6-100 photocatalyst specifically includes the following steps:

[0063] (1) The preparation method of ZIS photocatalyst

[0064] ZnIn2S4 without vacancy was synthesized according to the existing hydrothermal method. 0.4 mmol (0.05 g) of ZnCl2, 0.8 mmol (0.23 g) of InCl3·4H2O and 3.2 mmol (0.24 g) of thioacetamide were dissolved in 15 mL of ethanol and 15 mL of H2O, and ultrasonic treatment was performed for 5 min. The mixture was transferred into a polytetrafluoroethylene-lined high-pressure reaction kettle (with a capacity of 50 mL) and sealed. The mixture was heated at 353 K for 24 h, and then naturally cooled to room temperature. The supernatant was sucked up with a plastic pipette, and the obtained grayish yellow product was collected by centrifugation and washed with H2O and ethanol for 3 times, respectively. The product was dried in an oven at 353 K for one night to obtain a ZIS photocatalyst.

[0065] (2) Preparation of ZIS / [Bmim]PF6-100 photocatalyst

[0066] 20 mg of the ZIS photocatalyst prepared in step (1), 45 mL of acetonitrile and 5 mL of TEOA were added into a multifunctional photochemical reaction sealed reactor, and 100 μL of [Bmim]PF6 was added in situ to obtain a ZIS / [Bmim]PF6-100 photocatalyst.

[0067] Comparative Example 2

[0068] A ZIS photocatalyst was prepared by the same method as in (1) of Comparative Example 1.

[0069] Comparative Example 3

[0070] A V Zn A ZIS photocatalyst was prepared by the same method as in (1) of Example 1.

[0071] Comparative Example 4

[0072] An ionic liquid [Bmim]PF6 was purchased from Titan Science and Technology Exploration Platform.

[0073] Comparative Example 5

[0074] An indium sulfide (IS) photocatalyst was prepared by the same method as in Example 1, except that the amount of thioacetamide added in step (1) was changed to 0.8 mmol (0.06 g).

[0075] It was found through detection that when the amount of thioacetamide added in step (1) was changed to 0.8 mmol (0.06 g), i.e., the molar ratio of ZnCl2, InCl3·4H2O and thioacetamide was 1:2:2, the reaction could only generate indium sulfide (IS), and ZIS could not be generated. Therefore, to generate ZIS, the sulfur source must be added in excess.

[0076] Example 6

[0077] A method for producing syngas using photocatalysts prepared in Examples 1-4 and Comparative Examples 1-4 includes the following steps:

[0078] 20 mg of photocatalyst, 45 mL of acetonitrile (MeCN), and 5 mL of triethanolamine (TEOA) were added to a sealed reactor (110 mL capacity). The reactor was evacuated and purged several times with pure CO2 to achieve a partial pressure of 0.04 MPa. A 300 W Xe lamp with an AM 1.5G filter was used to simulate sunlight. During the photocatalytic process, the reaction system was vigorously stirred with a magnetic stirrer. After each hour of reaction, the products were detected online using gas chromatography (GC 7900) and quantified by comparing the peak area with that of pure standards. The products were detected using a flame ionization detector (FID) and a thermal conductivity detector (TCD).

[0079] The photocatalysts prepared in Examples 1-5 and Comparative Examples 1-4 were subjected to photocatalytic CO2 reduction to syngas under AM1.5G illumination at a temperature of 298 K.

[0080] Characterization data for some of the materials obtained in the above embodiments and comparative examples are as follows:

[0081] Figure 1 The image shown is of V prepared in Example 1 of this invention. Zn -ZIS / [Bmim]PF6-100 photocatalyst and ZIS / [Bmim]PF6-100, ZIS and V prepared in Comparative Examples 1-3 Zn -ZIS X-ray diffraction pattern; and by Figure 1 It can be seen that the diffraction peaks of Example 1 and Comparative Examples 1-3 belong to the hexagonal phase of ZnIn2S4 (JCPDS 65-2023), proving that V Zn -ZIS / [Bmim]PF6-100 successfully synthesized.

[0082] Figure 2 The image shown is of V prepared in Example 1 of this invention. Zn -ZIS / [Bmim]PF6-100 photocatalyst and ZIS / [Bmim]PF6-100, ZIS and V prepared in Comparative Examples 1, 3-4 Zn - Fourier transform infrared spectra of ZIS; Comparative Examples 1 and 4 at 813 cm⁻¹ -1 The IR peak is observed at 1472 cm⁻¹, which is due to the in-plane bending vibration of the PF bond. Furthermore, an IR peak is observed at 1472 cm⁻¹. -1 and 1575 cm-1 The peaks at 813 cm⁻¹ can be attributed to the stretching vibrations of the C=C and C=N bonds on the imidazole ring, respectively. Notably, in Example 1, the peak at 813 cm⁻¹... -1 The disappearance of the IR peak at that location may be attributed to the binding of [Bmim]PF6 with Zn vacancies.

[0083] Figure 3 The image shown is of V prepared in Comparative Example 3 of this invention. Zn -Zeta potential diagrams of ZIS nanocatalyst and Comparative Example 4 [Bmim]PF6; The Zeta potential diagrams show that Comparative Example 3 is negatively charged and Comparative Example 4 is positively charged, indicating that the synthesis of Example 1 may be attributed to V. Zn - Self-assembly of ZIS nanocatalysts with [Bmim]PF6.

[0084] Figure 4 The image shown is of V prepared in Example 1 of this invention. Zn -ZIS / [Bmim]PF6-100 photocatalyst and V prepared in Comparative Example 3 Zn -ZIS electron paramagnetic resonance test pattern; the test results show that the g value of Example 1 and Comparative Example 3 is 2.0039, indicating that V Zn The concentration was higher. Meanwhile, the diffraction peak of Example 1 was lower than that of Comparative Example 3, possibly because [Bmim]PF6 filled the Zn vacancies.

[0085] Figure 5 The image shown is of V obtained in Example 1 of the present invention. Zn -ZIS / [Bmim]PF6-100 photocatalyst and V prepared in Comparative Example 3 Zn -ZIS X-ray photoelectron spectroscopy; XPS measurements were performed to further determine the direction of electron transfer. Figure 5 As shown, compared with Comparative Example 3, the binding energies of Zn 2p, In 3d, and S 2p in Example 1 show a significant shift to higher energies, indicating that charge transfers from V... Zn -ZIS is transferred to [Bmim]PF6.

[0086] Figure 6 The image shown is of V obtained in Example 1 of the present invention. Zn Field emission scanning electron microscope (SEM) image (shown as a) and transmission electron microscope (TEM) image (shown as b) of ZIS / [Bmim]PF6-100 photocatalyst, and V prepared in Comparative Example 3. Zn - Transmission electron microscopy (TEM) image (shown as c) and energy scattering spectrum (shown as d) of ZIS; by Figure 6 It can be seen that both Example 1 and Comparative Example 3 exhibit a nanoflower-like structure, and the energy scattering spectroscopy test results show that C, N, P, F, Zn, In and S elements are present and uniformly distributed.

[0087] Figure 7 V Zn The test performance test chart of the photocatalytic production of synthesis gas of the ZIS / [Bmim]PF6-100 photocatalyst and the ZIS and V Figure 7 V Zn The photocatalytic production of synthesis gas of the ZIS / [Bmim]PF6-100 gradually increased over time.

[0088] Figure 8 V Zn The test performance test chart of the photocatalytic production of synthesis gas of the ZIS / [Bmim]PF6-100 photocatalyst and the ZIS and V Zn The test performance test chart of the photocatalytic production of synthesis gas of the ZIS photocatalyst; in comparison, the comparative example 1 and the comparative example 2 exhibited poor activity, and the ZIS without Zn vacancies did not improve the catalytic effect after adding [Bmim]PF6, which illustrated the importance of introducing Zn vacancies. At the same time, compared with the comparative example 3, the catalytic effect of the example 1 was greatly improved, the yield of H2 was increased from 21.54 mmol g -1 h -1 to 33.41 mmol g -1 h -1 , the yield of CO was increased from 82.39 mmol g -1 h -1 to 155.38 mmol g -1 h -1 This further illustrates the importance of the synergistic effect of the ionic liquid and the defects for the photocatalytic reduction of CO2 to produce synthesis gas.

[0089] Figure 9 V Zn The test performance test chart of the photocatalytic production of synthesis gas of the ZIS / [Bmim]PF6-100 photocatalyst and the V Zn ZIS / [Bmim]PF6-50, V Zn ZIS / [Bmim]PF6-200, V Zn ZIS / [Bmim]PF6-300, V Zn The test performance test chart of the photocatalytic production of synthesis gas of the ZIS / [Bmim]PF6-100 photocatalyst and the V Figure 9As shown, the syngas yield exhibited a volcanic pattern with increasing [Bmim]PF6 content, reaching 33.565 mmol g at an addition amount of 100 μL. -1 h -1 The highest yield.

[0090] Figure 10 The image shown is of V obtained in Example 1 of the present invention. Zn The performance test graph of the ZIS / [Bmim]PF6-100 photocatalyst for 12 hours of photocatalytic syngas production is shown. To evaluate the stability of the catalyst, this invention observed that the syngas yield steadily increased after 12 hours of continuous illumination. This indicates that the photocatalyst of this invention has good catalytic activity and cycle stability.

[0091] Figure 11 The image shown is of V prepared in Example 1 of this invention. Zn -ZIS / [Bmim]PF6-100 photocatalyst and ZIS / [Bmim]PF6-100, ZIS and V prepared in Comparative Examples 1-3 Zn - Performance test diagram of ZIS photocatalyst for syngas production under 15% CO2 conditions; Under 15% dilute CO2 conditions, the performance experiment verified that the synergistic effect of Zn vacancies and ionic liquids enhanced the conversion of syngas, which indicates that the synergy of Zn vacancies and ionic liquids may be beneficial to CO2 capture, further proving its potential for industrial application.

[0092] In summary, the method for preparing the catalyst of the present invention is simple to operate and low in cost. The obtained catalyst has a nano-flower-like morphology and high catalytic activity and stability, making it a promising photocatalyst.

[0093] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An ionic liquid synergistic defective ZnIn2S4 photocatalyst, characterized in that, The ionic liquid cooperates with the defective ZnIn2S4 photocatalyst to include V Zn - ZIS carrier and ionic liquid dispersed on the V Zn - ZIS carrier Wherein, the V Zn The ZIS carrier is ZnIn2S4 containing Zn vacancies, and the V Zn There is an electron transfer between the ZIS carrier and the ionic liquid; the ionic liquid is dispersed in the V Zn In the Zn vacancies in the ZIS carrier; The ionic liquid comprises at least one of [Bmim]PF6, [EMIm]NTF2, [EMIm]Br, BMIC, [Emim]BF4, [Emim][OAc], [EMIM]PF6. 2.The ionic liquid synergistic defective ZnIn2S4 photocatalyst according to claim 1, characterized in that, The V Zn The ZIS carrier presents a nanoflower-like structure. 3.The ionic liquid synergistic defective ZnIn2S4 photocatalyst according to claim 1, characterized in that, The V Zn The ratio of ZIS carrier to ionic liquid is 20 mg: 50 μL ~ 1000 μL. 4.The ionic liquid synergistic defective ZnIn2S4 photocatalyst according to claim 1, characterized in that, The V Zn The method for preparing the ZIS carrier comprises: 0.4 mmol of ZnCl2, 0.8 mmol of InCl3·4H2O and 3.2 mmol of thioacetamide are dissolved in 15 mL of ethanol and 15 mL of H2O to obtain a mixture; The mixture was transferred to a reaction kettle, sealed, heated at 453 K for 24 h, after natural cooling to room temperature, the supernatant was sucked, the obtained grayish yellow product was collected by centrifugation, washed, and dried to obtain V Zn - ZIS carrier.

5. The method for preparing the ionic liquid synergistic defective ZnIn2S4 photocatalyst according to any one of claims 1-4, characterized in that, The preparation method comprises the following steps: S1, preparation of V Zn - ZIS carrier; S2, dispersing the ionic liquid in the V Zn - on the ZIS support, obtaining the ionic liquid-assisted defective ZnIn2S4 photocatalyst.

6. The preparation method according to claim 5, characterized in that, S2 comprises the following specific steps: V Zn ZIS carrier, acetonitrile is added into the container, and the ionic liquid is added in situ, mixed uniformly, dried, and an ionic liquid coordinated defect ZnIn2S4 photocatalyst is obtained.

7. The production method according to claim 6, characterized by, V Zn The ratio of the addition of ZIS support, acetonitrile, TEOA and ionic liquid is 20 mg: 45 mL: 5 mL: 50 μL ~ 1000 μL.

8. Use of the ionic liquid synergistic defective ZnIn2S4 photocatalyst according to any one of claims 1-4 in photocatalytic reduction of CO2 to produce synthetic gas.

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