Preparation and application of a stable metal halide perovskite microcrystalline material with photocatalytic properties

Abstract

This invention relates to the preparation and application of a stable metal halide perovskite microcrystalline material with photocatalytic properties, belonging to the technical field of metal halide perovskite material preparation. The invention utilizes an anti-solvent method to dissolve cesium chloride (CsCl), copper chloride (CuCl2), and natural lecithin in dimethyl sulfoxide (DMSO) to form a homogeneous precursor solution. This solution is then rapidly added to isopropanol under vigorous stirring, and the reaction is quickly completed. Centrifugation yields lecithin-modified metal halide perovskite microcrystalline material (Cs2CuCl4). The lecithin-modified metal halide perovskite microcrystalline material (Cs2CuCl4) prepared by this invention exhibits good photocatalytic performance and excellent stability. Therefore, the lecithin-modified metal halide perovskite material (Cs2CuCl4) prepared by this invention shows great application potential in the field of photocatalysis.

Description

Technical Field

[0001] This invention belongs to the field of metal halide material preparation technology, specifically relating to the preparation and application of a stable metal halide perovskite microcrystalline material with photocatalytic properties. Background Technology

[0002] Over the past few decades, over-reliance on fossil fuels has led to severe energy and environmental problems. Excessive atmospheric carbon dioxide concentrations have caused global warming and glacial melting. Utilizing photocatalytic materials to convert CO2 into chemical feedstocks or fuels such as CO, CH4, and CH3OH can solve both energy shortages and environmental issues. Many nanostructured materials (such as metal oxides, metal sulfides, and metal halide perovskites) have been developed for photocatalytic CO2 reduction. In recent years, perovskites have attracted widespread attention due to their inexpensive preparation processes and excellent electronic and optical properties. Perovskites are considered ideal candidate materials for photocatalysts. However, the stability of perovskite materials and their severe charge recombination problems remain to be solved.

[0003] Cs₂CuCl₄ is a metal halide perovskite material with high absorption, high photon emission, and high charge carrier mobility. Organic ligands can be used to regulate the final size and shape during the synthesis of metal halide perovskites. Enhancing the coordination strength between the ligands and the perovskite surface stabilizes its crystal structure, improves the stability of the perovskite, and thus protects its optical properties.

[0004] To improve the stability of metal halide perovskite materials used in photocatalysis, it is necessary to study a new preparation method to synthesize Cs2CuCl4 microcrystals containing natural lecithin ligands, and to investigate the application of the corresponding Cs2CuCl4 microcrystals in photocatalysis. Summary of the Invention

[0005] In view of this, one objective of the present invention is to provide a method for preparing a stable lecithin-modified metal halide perovskite microcrystalline material with photocatalytic properties; another objective is to provide a stable lecithin-modified metal halide perovskite microcrystalline material with photocatalytic properties; and a third objective is to provide an application of a stable lecithin-modified metal halide perovskite microcrystalline material with photocatalytic properties in the field of photocatalytic CO2.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] 1. A method for preparing a stable metal halide perovskite microcrystalline material with photocatalytic properties, the preparation method comprising the following steps:

[0008] (1) Add cesium chloride (CsCl), copper chloride (CuCl2) and natural lecithin to dimethyl sulfoxide, stir to mix evenly and dissolve to form a precursor solution;

[0009] (2) The precursor solution was added to isopropanol (IPA) under stirring within 0.5 min to react and obtain a reaction mixture;

[0010] (3) After centrifuging the reaction mixture to remove the supernatant, a precipitate is obtained and vacuum dried to obtain a stable lecithin-modified metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) with photocatalytic properties.

[0011] Preferably, in step (1), the molar volume ratio of cesium chloride (CsCl), copper chloride (CuCl2), natural lecithin (Soybean Lecithin) and dimethyl sulfoxide is 10:5:1:1 mmol:mmol:mmol:ml.

[0012] Preferably, in step (2), the volume ratio of the precursor solution to isopropanol is 0.5 to 1.5:10, and the reaction time is 1 to 2 minutes.

[0013] Preferably, in step (2), the centrifugation speed is 9000-10000 r / min and the centrifugation time is 5-10 min, and the vacuum drying temperature is 60-80℃ and the time is 24-48 h.

[0014] 2. A stable metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) with photocatalytic properties prepared according to the above preparation method.

[0015] 3. Application of the above-mentioned stable metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) with photocatalytic properties in photocatalytic CO2 conversion.

[0016] The beneficial effects of this invention are as follows: This invention provides a method for preparing stable metal halide perovskite microcrystalline materials with photocatalytic performance, mainly using CsCl, CuCl2, and natural lecithin as raw materials, and preparing them by adding dimethyl sulfoxide and isopropanol (IPA). The stable lecithin-modified metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) prepared by this invention achieves the purpose of modification by forming surface ligands on the surface of natural lecithin on Cs2CuCl4. It has the characteristics of high absorption, high efficiency of charge carrier mobility, and good photocatalytic performance, and has good application prospects in photocatalytic CO2 conversion. Moreover, the synthesis method is simple, easy to operate, and does not require high-end equipment. It has the advantages of low cost and low energy consumption, and is suitable for large-scale production.

[0017] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0018] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0019] Figure 1 The flowchart shows the lecithin-modified metal halide perovskite microcrystalline material (Cs2CuCl4) prepared in Example 1;

[0020] Figure 2 The X-ray powder diffraction (XRD) patterns of the metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) prepared in Example 1 and the unmodified Cs2CuCl4 are shown.

[0021] Figure 3 The image shows the scanning electron microscope (SEM) images of the metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) prepared in Example 1, where a is Cs2CuCl4 and b is lecithin-modified Cs2CuCl4.

[0022] Figure 4 The UV-Vis absorption spectra (Abs) of Cs2CuCl4 (a) without lecithin modification and the metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) (b) prepared in Example 1.

[0023] Figure 5Photocatalytic CO2 conversion effects of unmodified Cs2CuCl4 and the metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) prepared in Example 1. Detailed Implementation

[0024] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0025] Example 1

[0026] A stable lecithin-modified metal halide perovskite microcrystalline material with photocatalytic properties (lecithin-modified Cs2CuCl4) is prepared as follows: Figure 1 As shown, the specific preparation method includes the following steps:

[0027] (1) Add 0.3367g of cesium chloride (CsCl), 0.1344g of copper chloride (CuCl2) and 0.1221g of natural lecithin (Soybean Lecithin) to 1ml of dimethyl sulfoxide, stir for 5min to mix evenly and dissolve to form a precursor solution;

[0028] (2) Add 1.0 ml of the precursor solution to 10 ml of isopropanol (IPA) under stirring at 10000 rpm within 0.5 min and react for 1 min to obtain the reaction mixture;

[0029] (3) The reaction mixture was centrifuged at 10,000 rpm for 5 min to remove the supernatant and a precipitate was obtained. The precipitate was then vacuum dried in a vacuum drying oven at 60°C for 24 h to obtain a stable metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) with photocatalytic properties.

[0030] Example 2

[0031] A stable metal halide perovskite microcrystalline material with photocatalytic properties (lecithin-modified Cs2CuCl4) is prepared by the following steps:

[0032] (1) Add 0.3367g of cesium chloride (CsCl), 0.1344g of copper chloride (CuCl2) and 0.1221g of natural lecithin (Soybean Lecithin) to 1ml of dimethyl sulfoxide, stir for 5min to mix evenly and dissolve to form a precursor solution;

[0033] (2) Add 0.5 ml of the precursor solution to 10 ml of isopropanol (IPA) under stirring at 9000 rpm within 0.5 min, and react for 2 min to obtain the reaction mixture;

[0034] (3) The reaction mixture was centrifuged at 9000 rpm for 5 min to remove the supernatant and a precipitate was obtained. The precipitate was then vacuum dried in a vacuum drying oven at 80°C for 48 h to obtain a stable metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) with photocatalytic properties.

[0035] Performance testing

[0036] The stable metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) prepared in Examples 1 and 2 was used as a sample to test its performance, as detailed below:

[0037] The metal halide perovskite microcrystalline material (lecithin-modified Cs₂CuCl₄) and Cs₂CuCl₄ prepared in Example 1 were subjected to X-ray powder diffraction tests, and the results are as follows: Figure 2 As shown. From Figure 2 It can be seen that the diffraction characteristic peaks of the metal halide perovskite microcrystalline materials prepared in Examples 1 and 2 are consistent with the characteristic peaks of the standard comparison card (PDF#72-0362), indicating the successful synthesis of lecithin-modified Cs2CuCl4. On the other hand, XRD shows that the phase purity of Cs2CuCl4 prepared by lecithin modification is almost unaffected.

[0038] The metal halide perovskite microcrystalline materials (lecithin-modified Cs2CuCl4) prepared in Examples 1 and 2 have high phase purity and orthorhombic crystal structure characteristics.

[0039] Scanning electron microscopy (SEM) analysis was performed on the metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) prepared in Example 1 and the unmodified Cs2CuCl4. The results are as follows: Figure 3 As shown, a is Cs₂CuCl₄ and b is lecithin-modified Cs₂CuCl₄. From Figure 3It can be seen that, compared with Cs2CuCl4 without ligand lecithin, the particle size of the lecithin-modified metal halide perovskite microcrystalline material (Cs2CuCl4) prepared in Example 1 is significantly reduced, which is more conducive to CO2 adsorption and thus promotes photocatalytic performance.

[0040] The unmodified Cs2CuCl4 (a) and the metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) (b) prepared in Example 1 were subjected to UV-Vis absorption spectroscopy (Abs) analysis. The results are as follows: Figure 4 As shown. From Figure 4 It can be seen that, compared with Cs2CuCl4 that has not been modified with lecithin, the metal halide perovskite microcrystalline material prepared in Example 1 has better visible light absorption characteristics.

[0041] Photocatalytic CO2 conversion was performed on unmodified Cs2CuCl4 and the metal halide perovskite microcrystalline material prepared in Example 1 (lecithin-modified Cs2CuCl4). The results are as follows: Figure 5 As shown. From Figure 5 It can be seen that the metal halide perovskite microcrystalline material (lecithin-modified Cs2CuCl4) prepared in Example 1 has better CO2 conversion performance than the unmodified Cs2CuCl4.

[0042] Similarly, the metal halide perovskite microcrystalline materials (lecithin-modified Cs2CuCl4) prepared in Examples 2 and 3 were subjected to the above-mentioned performance tests. The results were similar to those of the metal halide perovskite microcrystalline materials (lecithin-modified Cs2CuCl4) prepared in Example 1, all of which have good visible light absorption characteristics and high CO2 conversion efficiency.

[0043] In summary, this invention provides a method for preparing stable perovskite microcrystals with excellent photocatalytic performance, as well as the resulting product. The method uses CuCl2, CsCl, and natural lecithin as raw materials to prepare lecithin-modified Cs2CuCl4 perovskite material via an anti-solvent method. Weighed CuCl2, CsCl, and natural lecithin are added to a solution containing 1 ml of dimethyl sulfoxide to obtain a precursor solution. This precursor solution is then added to 10 ml of isopropanol under vigorous stirring, and the reaction is rapidly completed within 1-2 minutes, yielding stable metal halide perovskite microcrystals (lecithin-modified Cs2CuCl4). This material exhibits excellent stability and good photocatalytic performance; therefore, the stable metal halide perovskite microcrystals (lecithin-modified Cs2CuCl4) prepared by this invention shows great application potential in the field of photocatalysis. Furthermore, the synthesis method for this perovskite material is very simple, easy to operate, requires low-end equipment, is low-cost, low-energy, and suitable for large-scale production.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a stable metal halide perovskite microcrystalline material with photocatalytic properties, characterized in that, The preparation method includes the following steps: (1) Cesium chloride, copper chloride and natural lecithin were added to dimethyl sulfoxide and stirred until they were mixed evenly and dissolved to form a precursor solution; the molar volume ratio of cesium chloride, copper chloride, natural lecithin and dimethyl sulfoxide was 10 mmol: 5 mmol: 1 mmol: 1 ml. (2) The precursor solution was added to isopropanol under stirring within 0.5 min to react and obtain a reaction mixture; (3) After centrifuging the reaction mixture to remove the supernatant, a precipitate is obtained and vacuum dried to obtain a stable lecithin-modified metal halide perovskite microcrystalline material with photocatalytic properties.

2. The preparation method according to claim 1, characterized in that, In step (2), the volume ratio of the precursor solution to isopropanol is 0.5 to 1.5:10, and the reaction time is 1 to 2 minutes.

3. The preparation method according to claim 1, characterized in that, In step (3), the centrifugation speed is 9000-10000 r / min and the centrifugation time is 5-10 min, and the vacuum drying temperature is 60-80℃ and the time is 24-48 h.

4. A stable metal halide perovskite microcrystalline material with photocatalytic properties prepared by the preparation method according to any one of claims 1 to 3.

5. The application of the stable metal halide perovskite microcrystalline material with photocatalytic properties as described in claim 4 in photocatalytic CO2 conversion.

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