Pd-loaded Cs2SnCl6 perovskite material and preparation method and application thereof

Abstract

The invention belongs to the technical field of catalyst preparation, and particularly relates to a Pd-supported Cs2SnCl6 perovskite material and a preparation method and application thereof, and the preparation method is easy to operate, simple in process and controllable in cost; according to the Pd-loaded Cs2SnCl6 perovskite material, the characteristic of water resistance of a carrier and the characteristic of surface plasmon resonance of Pd nanoparticles are combined, so that the absorption spectrum range of the material can be effectively widened, the carrier transport capacity in the photo-assisted electro-catalysis process is improved, the overpotential of the material in an oxygen evolution reaction is reduced, and the catalytic activity of the material is further improved.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to Pd-supported Cs2SnCl6 perovskite materials, their preparation methods, and applications. Background Technology

[0002] Efficient and economical energy storage solutions are crucial for managing intermittent renewable energy sources, greatly stimulating interest in functional perovskite materials. Perovskites are a unique class of ionic crystals comprising various oxide and halide structures with similar octahedral coordination structures. Oxide perovskites are widely recognized as promising materials in electrocatalysis, photocatalysis, and photovoltaics. Their catalytic activity as electrode materials often stems from abundant oxygen vacancies. In contrast, halide perovskites possess superior physical properties, including long carrier diffusion lengths, high carrier mobilities, and excellent defect tolerance, making them highly suitable for optoelectronic devices. Compared to oxide perovskites, metal halide perovskites have inherently softer ionic lattices, granting them greater flexibility in electronic and crystal structures. This structural flexibility offers potential advantages for customizing electrocatalysis-related performance. However, the inherent instability of many halide perovskites under high humidity conditions is a major challenge. Overcoming this instability is a key prerequisite for realizing their potential as practical electrocatalysts.

[0003] Given the critical challenge of water stability in halide perovskite electrocatalysts, constructing heterojunction materials is the most widely reported strategy for enhancing the stability of halide perovskites in the literature. For example, MAPbBr X I 3-X (x=0,1,2,3) Halide perovskite nanocrystals embedded in an aluminum phosphate zeolite framework (AlPO-5) have been used for a novel application in efficient oxygen electrocatalysis in aqueous media. The AlPO-5 matrix not only significantly enhances the degradation resistance of perovskite nanocrystals in aqueous environments but also optimizes the adsorption free energy of oxygen-containing intermediates at the MAPbX3 / α-PbO2 interface. Despite this significant progress, research on the electrocatalysis of halide perovskites is still in its early stages, mainly limited to the introduction of oxygen vacancies and the preparation of stable and efficient perovskite electrocatalysts. Another key area of ​​research is how to apply the excellent photoelectric properties of halide perovskite materials to the field of oxygen evolution electrocatalysis. Summary of the Invention

[0004] To address the problems raised in the background art, this invention provides Pd-supported Cs2SnCl6 perovskite materials, their preparation methods, and applications.

[0005] The technical solution of the present invention is as follows: This invention provides a method for preparing Pd-supported Cs₂SnCl₆ perovskite material, comprising the following steps: (1) Cesium chloride and tin chloride pentahydrate were mixed in hydrochloric acid solution and stirred until completely dissolved to obtain a mixed solution; the mixed solution was heated at 160-200℃, cooled, filtered, washed and dried to obtain Cs2SnCl6 perovskite support; (2) Cs2SnCl6 perovskite support and palladium acetylacetone were dispersed in anhydrous ethanol, mixed, and heated at 55-65℃. After the reaction was completed, the mixture was filtered and dried to obtain Pd-supported Cs2SnCl6 perovskite material.

[0006] Further, in step (2), the mass ratio of the Cs2SnCl6 perovskite support to palladium acetylacetone is 50:0.5-2.0; the mass-to-volume ratio of the Cs2SnCl6 perovskite support to anhydrous ethanol is 50mg:18-22mL; and the mass-to-volume ratio of the Cs2SnCl6 perovskite support to the mixed solution is 50mg:36-44mL.

[0007] Further, in step (1), the molar ratio of cesium chloride and tin chloride pentahydrate is (1.8-2.2):1; the molar volume ratio of tin chloride pentahydrate to hydrochloric acid solution is 1 mmol: 4-6 mL.

[0008] Further, in step (1), the heating time is 10-14 hours; in step (2), the heating time is 10-14 hours.

[0009] In addition, it also includes: Pd-supported Cs2SnCl6 perovskite material was immersed in hydrogen peroxide solution to obtain oxygen vacancy-modified Pd-supported Cs2SnCl6 perovskite material.

[0010] Preferably, the Pd-supported Cs2SnCl6 perovskite material is prepared by a mass ratio of Cs2SnCl6 perovskite support to palladium acetylacetone of 50:1.0-1.8.

[0011] Furthermore, the soaking time is 20-40 seconds.

[0012] The present invention also provides a Pd-supported Cs2SnCl6 perovskite material prepared by the preparation method described above.

[0013] The present invention also provides an application of the Pd-supported Cs2SnCl6 perovskite material in energy storage.

[0014] Furthermore, the Pd-supported Cs2SnCl6 perovskite material is used as an electrocatalytic oxygen evolution reaction catalyst for energy storage.

[0015] Beneficial effects The preparation method of Pd-supported Cs2SnCl6 perovskite material provided by this invention is simple, easy to operate, and cost-controllable. The Pd-supported Cs2SnCl6 perovskite material, combined with the water-resistant characteristics of the support and the surface plasmon resonance characteristics of Pd nanoparticles, can effectively broaden the absorption spectrum range of the material, thereby improving the carrier transport capacity in the photo-assisted electrocatalysis process, reducing the overpotential of the material in the oxygen evolution reaction, and further improving the catalytic activity of the material.

[0016] The Pd-supported Cs2SnCl6 perovskite material provided by this invention combines the excellent photoelectric properties of the Cs2SnCl6 perovskite support with the high catalytic activity of Pd nanoparticles. At the same time, oxygen vacancies are introduced through hydrogen peroxide treatment. In the electrocatalytic oxygen evolution reaction, this material exhibits excellent performance, with catalytic performance significantly better than commercial ruthenium dioxide. It also has good stability and has significant advantages in energy storage and other fields. Attached Figure Description

[0017] Figure 1 X-ray diffraction patterns of different catalyst materials.

[0018] Figure 2 The images show the UV-Vis absorption spectra of different catalyst materials.

[0019] Figure 3 The graph shows the performance of different catalyst materials in a three-electrode system under dark conditions for electrocatalytic oxygen evolution.

[0020] Figure 4 The graph shows the performance of different catalyst materials in a three-electrode system under illumination for electrocatalytic oxygen evolution.

[0021] Figure 5 For O v -Cs2SnCl6@Pd 1.5 Catalyst stability test chart. Detailed Implementation

[0022] The following examples are intended to illustrate the present invention, and not to further limit the invention.

[0023] Example 1 Preparation of Cs2SnCl6 perovskite support Two mmol of cesium chloride (CsCl), one mmol of tin chloride pentahydrate (SnCl4·5H2O), and five mL of hydrochloric acid solution (12 mol / L) were heated at 180°C for 12 hours in a 25 mL polytetrafluoroethylene autoclave. The mixture was then slowly cooled to 30°C at a rate of 5°C / h. The resulting crystals were filtered, washed with ethanol, and dried overnight at 60°C to obtain the Cs2SnCl6 perovskite support.

[0024] Example 2 Preparation of Pd-supported Cs2SnCl6 perovskite materials with different Pd loadings Weigh out 50 mg of the Cs₂SnCl₆ perovskite support prepared in Example 1 and 0.5, 1, and 1.5 mg of palladium acetylacetone, respectively, disperse them in 20 mL of anhydrous ethanol, mix them, and heat at 60°C for 12 hours. The mixture is then filtered and dried at 60°C overnight to obtain Pd-supported Cs₂SnCl₆ perovskite materials with different Pd loadings, denoted as Cs₂SnCl₆@Pd. 0.5 Cs2SnCl6@Pd1 and Cs2SnCl6@Pd 1.5 (The subscript number of Pd represents the actual loading of Pd, in mg).

[0025] Example 3 Preparation of oxygen vacancy-modified Pd-supported Cs2SnCl6 perovskite materials Weigh out the Cs2SnCl6@Pd prepared in Example 2 1.5 20 mg of the material was immersed in a 10 mol / L hydrogen peroxide solution for 30 seconds to obtain an oxygen vacancy-modified Pd-supported Cs₂SnCl₆ perovskite material, named O. v -Cs2SnCl6@Pd 1.5 .

[0026] Next, the Cs2SnCl6 perovskite support obtained in Example 1 and the Cs2SnCl6@Pd support obtained in Example 2 were used. 0.5 Cs2SnCl6@Pd1 and Cs2SnCl6@Pd 1.5 O obtained in Example 3 v -Cs2SnCl6@Pd 1.5 Perform X-ray diffraction (XRD) analysis, such as Figure 1 .

[0027] The results showed that the characteristic diffraction peaks of the Cs2SnCl6 perovskite support perfectly matched those of the Cs2SnCl6 standard card (PDF#070-2413), proving the successful preparation of a pure-phase Cs2SnCl6 perovskite support with a complete crystal structure. Furthermore, Cs2SnCl6@Pd 0.5 Cs2SnCl6@Pd1 and Cs2SnCl6@Pd 1.5The XRD pattern of the sample is basically consistent with that of pure Cs2SnCl6 perovskite. The positions of the characteristic diffraction peaks are not significantly shifted, and only the peak intensities are slightly changed, proving that the loading of Pd did not change the crystal structure of Cs2SnCl6 perovskite. At the same time, the characteristic diffraction peaks of Pd (corresponding to PDF#067-1061) can be observed in the XRD pattern, proving that Pd nanoparticles were successfully loaded onto the surface of Cs2SnCl6 perovskite support.

[0028] Then, the Cs2SnCl6 perovskite support obtained in Example 1 and the Cs2SnCl6@Pd support obtained in Example 2 were used. 0.5 Cs2SnCl6@Pd1 and Cs2SnCl6@Pd 1.5 O obtained in Example 3 v -Cs2SnCl6@Pd 1.5 Perform ultraviolet-visible absorption spectroscopy analysis, such as Figure 2 .

[0029] The results showed that Cs2SnCl6@Pd1 and Ov-Cs2SnCl6@Pd 1.5 The absorption wavelength range of Cs2SnCl6@Pd1 is significantly broadened compared to pure Cs2SnCl6 perovskite (300-750nm). The absorption wavelength of Cs2SnCl6@Pd1 covers 300-750nm. 1.5 The absorption wavelength covers 300-800 nm, proving that increasing the Pd loading helps to further broaden the light absorption range of the material. Meanwhile, O... v -Cs2SnCl6@Pd 1.5 The absorption wavelength range was further broadened to 300-850 nm, compared to untreated Cs2SnCl6@Pd. 1.5 (300-800nm) The light absorption capacity is significantly enhanced, proving that hydrogen peroxide treatment successfully introduces oxygen vacancies, and that oxygen vacancies help improve the light absorption performance of the material.

[0030] Example 4 Electrocatalytic performance test Electrocatalytic oxygen evolution performance was tested using a three-electrode system, in which the Cs2SnCl6 perovskite support obtained in Example 1 and the Cs2SnCl6@Pd support obtained in Example 2 were selected respectively. 0.5 Cs2SnCl6@Pd1 and Cs2SnCl6@Pd 1.5 O obtained in Example 3 v -Cs2SnCl6@Pd 1.5Commercial RuO2 was used as the test sample to prepare the working electrode. The LSV curve scan rate was 0.005 V / s, the test voltage range was 0.8-2.2 V, and the electrolyte was 0.5 M H2SO4. The tests were conducted under dark conditions (…). Figure 3 ) and simulated sunlight conditions ( Figure 4 The test was conducted under the following conditions.

[0031] The catalytic performance test results under dark conditions are as follows: Figure 3 As shown, at 10mA / cm 2 At the given current density, the overpotentials of each sample are: Cs₂SnCl₆ 768mV, Cs₂SnCl₆@Pd₁ 668mV, and Cs₂SnCl₆@Pd₁ 668mV. 1.5 613 mV, Ov-Cs2SnCl6@Pd 1.5 378 mV. This shows that the Pd loading significantly reduces the overpotential of the Cs₂SnCl₆ perovskite, and the overpotential gradually decreases with increasing Pd loading; while O v -Cs2SnCl6@Pd 1.5 The introduction of oxygen vacancies further reduces the overpotential, resulting in excellent electrocatalytic performance under dark conditions.

[0032] The catalytic performance test results under light irradiation conditions are as follows: Figure 4 As shown, at 10 mA / cm 2 At the given current density, the overpotential of each sample decreased to varying degrees compared to the dark condition: Cs₂SnCl₆ 547mV, Cs₂SnCl₆@Pd₁ 447mV, Cs₂SnCl₆@Pd₂ 1.5 446mV, Ov-Cs2SnCl6@Pd 1.5 135mV. This result indicates that illumination conditions can effectively enhance the electrocatalytic performance of Pd-supported Cs₂SnCl₆ perovskite materials, where O v -Cs2SnCl6@Pd 1.5 The material exhibits the lowest overpotential under illumination, which is 300 mV lower than that of commercial RuO2, fully demonstrating its excellent photo-assisted electrocatalytic effect and verifying its application potential in the field of energy storage.

[0033] Example 5 Stability test like Figure 5 As shown, for catalyst O v -Cs2SnCl6@Pd 1.5 The current density remained essentially unchanged after 100 hours of electrocatalytic reaction, demonstrating the excellent stability of the catalyst.

Claims

1. A method for preparing a Pd-supported Cs₂SnCl₆ perovskite material, characterized in that, Includes the following steps: (1) Cesium chloride and tin chloride pentahydrate were mixed in hydrochloric acid solution and stirred until completely dissolved to obtain a mixed solution; the mixed solution was heated at 160-200℃, cooled, filtered, washed and dried to obtain Cs2SnCl6 perovskite support; (2) Cs2SnCl6 perovskite support and palladium acetylacetone were dispersed in anhydrous ethanol, mixed, and heated at 55-65℃. After the reaction was completed, the mixture was filtered and dried to obtain Pd-supported Cs2SnCl6 perovskite material.

2. The preparation method according to claim 1, characterized in that, In step (2), the mass ratio of the Cs2SnCl6 perovskite support to palladium acetylacetone is 50:0.5-2.0; the mass-volume ratio of the Cs2SnCl6 perovskite support to anhydrous ethanol is 50mg:18-22mL; and the mass-volume ratio of the Cs2SnCl6 perovskite support to the mixed solution is 50mg:36-44mL.

3. The preparation method according to claim 1, characterized in that, In step (1), the molar ratio of cesium chloride and tin chloride pentahydrate is (1.8-2.2):1; the molar volume ratio of tin chloride pentahydrate to hydrochloric acid solution is 1 mmol: 4-6 mL.

4. The preparation method according to claim 1, characterized in that, Step (1), heating time is 10-14 hours; Step (2), heating time is 10-14 hours.

5. The preparation method according to claim 1, characterized in that, Also includes: Pd-supported Cs2SnCl6 perovskite material was immersed in hydrogen peroxide solution to obtain oxygen vacancy-modified Pd-supported Cs2SnCl6 perovskite material.

6. The preparation method according to claim 5, characterized in that, The Pd-supported Cs2SnCl6 perovskite material is prepared by using a Cs2SnCl6 perovskite support and palladium acetylacetone in a mass ratio of 50:1.0-1.

8.

7. The preparation method according to claim 5, characterized in that, Soaking time is 20-40 seconds.

8. A Pd-supported Cs2SnCl6 perovskite material prepared by the preparation method according to any one of claims 1-7.

9. An application of the Pd-supported Cs2SnCl6 perovskite material as described in claim 8 in energy storage.

10. The application according to claim 9, characterized in that, The Pd-supported Cs2SnCl6 perovskite material is used as an electrocatalytic oxygen evolution reaction catalyst for energy storage.

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