Preparation and application of Cs3Bi2Br9 / S, N-rGO composite catalyst for photocatalytic synthesis of thiophosphonate

Abstract

The invention provides a preparation method of a Cs3Bi2Br9 / S, N-rGO photocatalyst for synthesizing thiophosphonate through photocatalytic oxidation-reduction coupling, a method of doping metal halogenated perovskite with S, N-rGO is adopted, and efficient catalytic activity and high stability of a metal halogenated perovskite material under a high-humidity condition are realized; the catalyst is adopted, a thiophenol substrate and phosphorus oxide are used as raw materials, water is used as a solvent, and high-efficiency and high-selectivity synthesis of the thiophosphonate derivative is realized through visible light irradiation in an air atmosphere at room temperature.

Description

Technical Field

[0001] The present invention belongs to the field of photocatalysts, and specifically relates to the preparation and application of a Cs3Bi2Br9 / S,N-rGO composite catalyst for photocatalytic synthesis of thiophosphonates. Background Art

[0002] Thiophosphonates, a class of compounds with broad application prospects in medicine, pesticides, and materials science, have attracted considerable attention for their synthesis. Given their unique chemical structure and biological activity, exploring efficient and environmentally friendly synthetic pathways is crucial for promoting their application.

[0003] Redox coupling is an important method for synthesizing thiophosphonates. However, practical implementation presents numerous challenges. The coupling between the sulfur atom and the phosphonate group requires precise redox conditions, and traditional synthesis methods often rely on high temperatures, high pressures, or toxic reagents, which not only increases production costs but also poses environmental risks. To overcome these challenges, researchers are actively developing novel, green, and efficient redox coupling systems. These systems aim to utilize milder reaction conditions, environmentally friendly redox agents, and optimized catalysts to achieve high selectivity and high yields for the synthesis of thiophosphonates. For example, electrochemical methods can achieve redox reactions at ambient temperature and pressure, avoiding the safety hazards associated with high temperatures and high pressures. Furthermore, the use of renewable resources as redox agents can reduce production costs and environmental pollution. Furthermore, advanced technologies such as photocatalysis have also been applied to the synthesis of thiophosphonates. Photocatalysis utilizes light energy to excite the catalyst to produce active species, enabling precise control of the redox reaction. This method is not only highly efficient and environmentally friendly, but also allows for mild reaction conditions, offering a new approach for the green synthesis of thiophosphonates. Consequently, current research focuses on developing fast and efficient photocatalytic redox coupling systems to achieve the green and highly selective synthesis of thiophosphonates. This will not only help promote the application of thiophosphonates in various fields, but also inject new vitality into promoting the sustainable development of chemical synthesis technology.

[0004] Metal halide perovskites (MHPs) have been widely used in photocatalysis due to their advantages, including long carrier lifetimes and high mobility, good defect tolerance, and easily tunable band gaps in the visible light region. However, due to the easy penetration of reactive oxygen species and water into the MHPs lattice, resulting in framework degradation, MHPs are structurally unstable in oxygen-rich and high-humidity environments, limiting their application research. Therefore, achieving high structural stability and catalytic activity of MHPs under high-humidity conditions remains an urgent challenge. Summary of the Invention

[0005] The first object of the present invention is to provide a preparation method of a Cs3Bi2Br9 / S,N-rGO composite catalyst for the photocatalytic synthesis of thiophosphonates; specifically: 1) Ultrasonically treat graphene oxide, thiourea and ethylene glycol for 30 minutes, transfer the solution to a stainless-steel autoclave with a polytetrafluoroethylene liner, and carry out a hydrothermal reaction at 180 °C for 10 hours. Obtain S,N-rGO powder by centrifugal separation; wash it 3-5 times with absolute ethanol and deionized water, and then dry it in a vacuum oven at 80 °C for 12 hours to obtain S,N-rGO;

[0006] 2) Mix cesium bromide, bismuth bromide, oleylamine and dimethyl sulfoxide and react, and then form a clear precursor solution at 60 °C and in a nitrogen atmosphere;

[0007] 3) Mix S,N-rGO, ethanol and oleic acid and stir evenly, add the precursor solution to the mixed solution, and stir vigorously at 80 °C;

[0008] 4) Centrifuge the solution obtained in step 3) at 7000 rpm for 5 minutes, discard the supernatant, wash the obtained yellow solid 3-5 times with n-hexane, and dry it at 60 °C under vacuum for 2 hours to obtain the catalyst.

[0009] Preferably, in step 1), the mass-volume ratio of graphene oxide, thiourea and ethylene glycol is 1.8-2.2 mg: 1 mg: 1.8-2.2 mL.

[0010] Preferably, in step 2), the mass-volume ratio of cesium bromide, bismuth bromide, oleylamine and dimethyl sulfoxide is 0.085 g: 0.120 g: 66 μL: 6 mL.

[0011] Preferably, in step 3), the mass-volume ratio of S,N-rGO, ethanol, oleic acid and the precursor solution is 20 mg: 6 mL: 0.6 mL: 0.6 mL.

[0012] Another object of the present invention is to provide the application of the above catalyst in the synthesis of thiophosphonates; specifically: Disperse Cs3Bi2Br9 / S,N-rGO, thiophenol substrate and phosphorus oxide in water, and irradiate the obtained system with visible light at room temperature in air until the substrate is completely converted; Centrifuge and recover the photocatalyst from the above reaction system for recycling; The obtained solution is extracted with an organic solvent, the organic phases are combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a thiophosphonate product.

[0013] Advantages and beneficial effects of the present invention:

[0014] (1) By using the method of doping metal halide perovskite with S,N-rGO, the high catalytic activity and high stability of metal halide perovskite materials under high-humidity conditions are achieved.

[0015] (2) The present invention uses thiophenol substrates and phosphorus oxides as raw materials, water as a solvent, and Cs3Bi2Br9 / S,N-rGO as a catalyst. Under visible light irradiation in an air atmosphere at room temperature, the efficient and highly selective synthesis of thiophosphonate derivatives is achieved. This method uses water as a solvent, which is green and efficient, has good functional group tolerance and excellent chemoselectivity, can achieve gram-scale production, and the reaction conditions are mild. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the synthesis of the Cs3Bi2Br9 / S,N-rGO composite catalyst of the present invention;

[0017] Figure 2 (a-c) are the transmission electron microscope images of Cs3Bi2Br9, S,N-rGO, and Cs3Bi2Br9 / S,N-rGO in Example 1 respectively, and (d) is the high-resolution transmission electron microscope image of Cs3Bi2Br9 / S,N-rGO;

[0018] Figure 3 1H NMR and 31P NMR spectra of S-(p-tolyl)diphenyl thiophosphonate synthesized in Example 2;

[0019] Figure 4 1H NMR and 31P NMR spectra of S-(4-methoxybenzyl)diphenyl thiophosphonate synthesized in Example 3;

[0020] Figure 5 1H NMR and 31P NMR spectra of S-pentyldiphenyl thiophosphate synthesized in Example 4;

[0021] Figure 6 1H NMR and 31P NMR spectra of S-(p-tolyl)bis(4-fluorophenyl) thiophosphonate synthesized in Example 5. DETAILED DESCRIPTION OF THE INVENTION

[0022] Example 1

[0023] 1) Preparation of S,N-doped graphene

[0024] First, 40 mg of graphene oxide, 20 mg of thiourea, and 40 mL of ethylene glycol were ultrasonically treated for 30 minutes. The solution was transferred to a stainless-steel autoclave lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 180 °C for 10 hours. The powder was obtained by centrifugation, washed 4 times with absolute ethanol and deionized water, and then dried in a vacuum oven at 80 °C for 12 hours to obtain S,N-doped graphene;

[0025] 2) Preparation of S,N-rGO-doped metal halide perovskite

[0026] 0.085 g of cesium bromide, 0.120 g of bismuth bromide, 66 μL of oleylamine and 6 mL of dimethyl sulfoxide were added to a three-necked flask, and then a clear precursor solution was formed in a nitrogen atmosphere at 60 °C. Subsequently, 20 mg of S,N-rGO, 6 mL of ethanol and 0.6 mL of oleic acid were added to a beaker and stirred evenly. 0.6 mL of the precursor solution was added to the mixed solution, and it was vigorously stirred at 80 °C. The reaction solution was collected by centrifugation at 7000 rpm for 5 minutes, the supernatant was discarded, and the obtained yellow solid was washed 4 times with n-hexane and dried at 60 °C under vacuum for 2 hours to obtain the composite photocatalyst (Cs3Bi2Br9 / S,N-rGO).

[0027] Using the composite photocatalyst (Cs3Bi2Br9 / S,N-rGO) prepared in Example 1 as the raw material, photocatalytic synthesis was carried out on different thiophenol substrates and phosphorus oxides, specifically as follows:

[0028] Example 2

[0029] In a 25 mL borosilicate glass reaction tube, p-methylbenzenethiol (12.4 mg, 0.10 mmol), diphenylphosphine oxide (30.3 mg, 0.15 mmol) and Cs3Bi2Br9 / S,N-rGO (5.0 mg) were dispersed in water (2.0 mL). Under room temperature air conditions, with an irradiation distance of 5.0 cm, it was irradiated and stirred with a 50 W blue LED for 6 hours; subsequently, the photocatalyst was recovered by centrifugation, and the obtained solution was extracted with an organic solvent from the reaction system 3 times, the organic phases were combined, dried, filtered, concentrated, and the target product S-(p-tolyl)diphenylphosphine sulfonate was obtained (isolation yield: 91%).

[0030] Example 3

[0031] In a 25 mL borosilicate glass reaction tube, p-methoxybenzyl mercaptan (15.4 mg, 0.10 mmol), diphenylphosphine oxide (30.3 mg, 0.15 mmol) and Cs3Bi2Br9 / S,N-rGO (5.0 mg) were dispersed in water (2.0 mL). Under room temperature air conditions, with an irradiation distance of 5.0 cm, it was irradiated and stirred with a 50 W blue LED for 6 hours; subsequently, the photocatalyst was recovered by centrifugation, and the obtained solution was extracted with an organic solvent from the reaction system 3 times, the organic phases were combined, dried, filtered, concentrated, and the target product S-(4-methoxybenzyl)diphenylphosphine sulfonate was obtained (isolation yield: 91%).

[0032] Example 4

[0033] In a 25 mL borosilicate glass reaction tube, pentanethiol (10.4 mg, 0.10 mmol), diphenylphosphine oxide (30.3 mg, 0.15 mmol) and Cs3Bi2Br9 / S,N-rGO (5.0 mg) were dispersed in water (2.0 mL). Under room temperature and air conditions, with an irradiation distance of 5.0 cm, a 50 W blue LED was used to irradiate and stir for 6 hours. Subsequently, the photocatalyst was recovered by centrifugation. The resulting solution was extracted with an organic solvent three times, the organic phases were combined, dried, filtered, concentrated, and the target product S-pentyldiphenyl thiophosphate (isolated yield: 73%) was obtained.

[0034] Example 5

[0035] In a 25 mL borosilicate glass reaction tube, p-methoxybenzyl mercaptan (15.4 mg, 0.10 mmol), bis(4-fluorophenyl)phosphine oxide (35.7 mg, 0.15 mmol) and Cs3Bi2Br9 / S,N-rGO (5.0 mg) were dispersed in water (2.0 mL). Under room temperature and air conditions, with an irradiation distance of 5.0 cm, a 50 W blue LED was used to irradiate and stir for 6 hours. Subsequently, the photocatalyst was recovered by centrifugation. The resulting solution was extracted with an organic solvent three times, the organic phases were combined, dried, filtered, concentrated, and the target product S-(p-tolyl)bis(4-fluorophenyl)thiophosphonate (isolated yield: 96%) was obtained.

Claims

1. Preparation method of Cs3Bi2Br9 / S,N-rGO composite catalyst for photocatalytic synthesis of thiophosphonate, characterized in that: Specifically: 1) Ultrasonically treat graphene oxide, thiourea and ethylene glycol for 30 minutes, transfer the solution to a stainless steel autoclave with a polytetrafluoroethylene lining, carry out hydrothermal reaction at 180 °C for 10 hours, and obtain S,N-rGO powder by centrifugal separation; Wash 3-5 times with absolute ethanol and deionized water, and then dry in a vacuum oven at 80 °C for 12 hours to obtain S,N-rGO; 2) Mix cesium bromide, bismuth bromide, oleylamine and dimethyl sulfoxide and react, and then form a clear precursor solution at 60 °C and in a nitrogen atmosphere; 3) Mix S,N-rGO, ethanol and oleic acid and stir evenly, add the precursor solution to the mixed solution, and stir vigorously at 80 °C; 4) Centrifuge the solution obtained in step 3) at 7000 rpm for 5 minutes, discard the supernatant, wash the obtained yellow solid with n-hexane 3-5 times, and dry at 60 °C under vacuum for 2 hours to obtain the catalyst.

2. The preparation method of a Cs3Bi2Br9 / S,N-rGO composite catalyst for the photocatalytic synthesis of thiophosphonate esters according to claim 1, characterized in that: The mass-volume ratio of the graphene oxide, thiourea and ethylene glycol is 1.8-2.2 mg: 1 mg: 1.8-2.2 mL.

3. The preparation method of a Cs3Bi2Br9 / S,N-rGO composite catalyst for the photocatalytic synthesis of thiophosphonate esters according to claim 1, characterized in that: The mass-volume ratio of the cesium bromide, bismuth bromide, oleylamine and dimethyl sulfoxide is 0.085 g: 0.120 g: 66 μL: 6 mL.

4. The preparation method of a Cs3Bi2Br9 / S,N-rGO composite catalyst for the photocatalytic synthesis of thiophosphonate esters according to claim 1, characterized in that: The mass-volume ratio of S,N-rGO, ethanol, oleic acid and the precursor solution is 20 mg: 6 mL: 0.6 mL: 0.6 mL.

5. Application of Cs3Bi2Br9 / S,N-rGO photocatalyst in the synthesis of thiophosphonates, characterized in that: Disperse Cs3Bi2Br9 / S,N-rGO, thiol substrate and phosphorus oxide in water, irradiate the obtained system with visible light at room temperature under air conditions until the substrate is completely converted; Centrifuge and recover the photocatalyst from the above reaction system for recycling; The obtained solution is extracted with an organic solvent, the organic phases are combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a thiophosphonate product.

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