CN-118237053-B - Preparation method and application of molybdenum selenide/oxygen defect bismuth oxybromide@ Jin Sanxiang Z-type heterojunction photocatalyst

Abstract

The invention relates to the technical field of nano full-spectrum photocatalytic materials, in particular to a preparation method of a molybdenum selenide/oxygen defect bismuth oxybromide@ Jin Sanxiang Z-heterojunction photocatalyst, which solves the problems of low photo-generated electron hole separation rate, narrow full-spectrum response range and poor stability of the existing bismuth-based photocatalyst. The preparation method comprises the steps of firstly preparing oxygen defect BiOBr nano-microspheres through a solvothermal method, then directly reacting tetrachloroauric acid with oleylamine in toluene to prepare small-particle-size-distribution monodisperse Au nano-particles, compositing the small-particle-size-distribution monodisperse Au nano-particles with the oxygen defect BiOBr to prepare a BiOBr@Au nano-microsphere core-shell structure, and finally preparing the MoSe 2 /oxygen defect BiOBr@Au three-phase composite material through a hydrothermal reaction. The catalyst has absorption capacity under full spectrum light, realizes the synergistic enhancement of carrier separation efficiency and strong redox capacity, shows excellent photocatalytic activity, and can efficiently degrade pollutants and produce hydrogen.

Inventors

• XU XIAOMING
• ZHU XIANHUI
• HUANG JIAYING
• YUAN RUIXIA
• JING GUOLIN
• ZHENG LIHUI
• CAO WENZHONG
• YANG SHAOGUI
• SUN CHENG

Assignees

• 东北石油大学

Dates

Publication Date

20260505

Application Date

20240329

Claims (10)

1. 1. The preparation method of the molybdenum selenide/oxygen defect bismuth oxybromide@ Jin Sanxiang Z-type heterojunction photocatalyst is characterized by comprising the following steps of: (1) Preparing nano flower BiOBr-OVs: Dissolving bismuth nitrate pentahydrate and polyvinylpyrrolidone-K30 into a mixed solution of ethylene glycol and deionized water through ultrasonic treatment and stirring, adding potassium bromide into the solution, stirring the solution at room temperature, transferring the finally obtained transparent solution into a 50mL high-pressure reaction kettle for reaction, centrifuging after the reaction is finished to obtain a product, washing with water and ethanol, and vacuum-drying at 60-80 ℃ for 5-7h to obtain a flower-type BiOBr-OVs sample with surface oxygen defect modification; (2) Preparation of BiOBr-OVs@Au: Mixing oleylamine containing tetrachloroauric acid with toluene, adding the mixture into a flask, heating the mixture to 60-80 ℃ for 5-6h under nitrogen protection and magnetic stirring, cooling the obtained product to room temperature, adding ethanol into the mixture, centrifuging to obtain Au nano particles, dispersing the Au nano particles into 20mL of heptane through ultrasonic and stirring to form a red dispersion, mixing the formed red dispersion with 3-mercaptopropionic acid into the flask, stirring the obtained mixed solution at room temperature, washing the precipitate with normal hexane and ethanol after centrifuging, dispersing the precipitate into normal hexane through ultrasonic and stirring to obtain Au nano particle suspension solution, mixing BiOBr-OVs with the Au nano particle suspension solution and normal hexane, stirring the obtained product at the ultrasonic and room temperature, and vacuum drying the obtained product at 50-70 ℃ for 2-3h to obtain a BiOBr-OVs@Au sample; (3) Preparing MoSe 2 /BiOBr-OVs@Au three-phase photocatalyst: Dispersing BiOBr-OVs@Au in 30mL of deionized water containing Na 2 MoO 4 ·2H 2 O by ultrasonic and stirring to form a suspension solid solution, gradually dropwise adding an N 2 H 4 ·2H 2 O solution of dissolved Se powder into the suspension solid solution under magnetic stirring, continuously stirring, transferring to a 50mL high-pressure reaction kettle, washing with water and ethanol, and freeze-drying to obtain the three-phase photocatalyst MoSe 2 /BiOBr@Au.
2. 2. The method for preparing the molybdenum selenide/oxygen-deficient bismuth oxybromide @ Jin Sanxiang Z-heterojunction photocatalyst according to claim 1, wherein in the step (1), the mass ratio of bismuth nitrate pentahydrate, polyvinylpyrrolidone-K30 and potassium bromide is 0.73:0.7:0.18.
3. 3. The method for preparing the molybdenum selenide/oxygen-deficient bismuth oxybromide @ Jin Sanxiang Z-heterojunction photocatalyst according to claim 1, wherein the volume ratio of deionized water to ethylene glycol in the step (1) is 1:1-1:6.
4. 4. The preparation method of the molybdenum selenide/oxygen defect bismuth oxybromide@ Jin Sanxiang Z-type heterojunction photocatalyst according to claim 1, wherein the mass fraction of the Au of the BiOBr-OVs@Au in the step (2) is 3% -9%.
5. 5. The method for preparing the molybdenum selenide/oxygen defect bismuth oxybromide@ Jin Sanxiang Z-type heterojunction photocatalyst according to claim 1, wherein the volume ratio of oleylamine to toluene in the step (2) is 1:9, and the volume ratio of n-hexane to ethanol is 2:1.
6. 6. The preparation method of the molybdenum selenide/oxygen defect bismuth oxybromide@ Jin Sanxiang Z-type heterojunction photocatalyst according to claim 1, wherein the mass fraction of MoSe 2 of MoSe 2 /BiOBr@Au in the step (3) is 4% -12%.
7. 7. The method for preparing the molybdenum selenide/oxygen defect bismuth oxybromide @ Jin Sanxiang Z-type heterojunction photocatalyst according to claim 1, wherein the reaction temperature in the autoclave in the step (1) is 120-200 ℃, the reaction time is 10-24h, and the reaction temperature in the autoclave in the step (3) is 150-200 ℃ and the reaction time is 12-48h.
8. 8. The three-phase photocatalyst MoSe 2 /BiOBr@Au prepared by the preparation method according to claim 1.
9. 9. Use of a three-phase photocatalyst according to claim 8, wherein the three-phase photocatalyst is useful for degrading contaminants.
10. 10. Use of a three-phase photocatalyst according to claim 8, wherein the three-phase photocatalyst is useful for photocatalytic hydrogen evolution.

Description

Preparation method and application of molybdenum selenide/oxygen defect bismuth oxybromide@ Jin Sanxiang Z-type heterojunction photocatalyst Technical Field The invention relates to the technical field of nano full-spectrum photocatalytic materials, in particular to a preparation method and application of a molybdenum selenide/oxygen defect bismuth oxybromide@ Jin Sanxiang Z-type heterojunction photocatalyst. Background At present, environmental problems caused by organic wastewater are paid attention to, and a commonly used removal method for the organic wastewater is a high-grade oxidation method, wherein the high-grade oxidation method has the advantages of low cost, easily controlled operation conditions, high wastewater treatment efficiency and the like. Among the numerous advanced oxidation technologies, the photocatalytic oxidation technology can realize deep mineralization of highly toxic and hardly biodegradable organic pollutants, so that attention is paid, but how to design a photocatalyst which is efficient, inexpensive, stable and full-spectrum to be used and is convenient for industrial production, and use the photocatalyst for treatment of organic pollution wastewater has become urgent. In recent years, due to the continuous consumption of fossil fuel and the increased environmental pollution caused by the combustion and utilization of fossil fuel, the current search for alternative energy sources and sustainable energy sources has been a concern, and from this point of view, hydrogen is the most attractive clean energy source because of its high energy density and pollution-free combustion products, and in this case, semiconductor photocatalytic hydrogen production is a very promising cleaning method, and the development of efficient photocatalysts has been attracting attention. BiOBr is a typical narrow bandgap layered compound semiconductor, the crystal configuration belongs to PbFCl types, and the space group is P4/nmm, and is classified as a typical tetragonal system. Compared with the conventional TiO 2 photocatalysis, the BiOBr has the advantages of narrower band gap, easy excitation by visible light and the like, but the BiOBr still has the defects of low photoproduction electron hole separation rate, narrow full spectrum response range, difficult mass production, poor stability and the like. In order to break through the bottlenecks, oxygen defects are introduced into the surface of the BiOBr to reduce potential barrier of interfacial charge transfer, and a heterojunction structure is constructed by the oxygen defects and other semiconductor materials, so that the transfer rate of carriers can be improved, the forbidden bandwidth of the BiOBr is compressed, and the photocatalytic activity of the BiOBr is obviously improved. Disclosure of Invention The invention provides a preparation method of a molybdenum selenide/oxygen defect bismuth oxybromide@ Jin Sanxiang Z-heterojunction photocatalyst, which aims to solve the problems of low photo-generated electron hole separation rate, narrow full spectral response range, difficulty in large-scale production and poor stability of the existing bismuth-based photocatalyst. The invention aims to provide a preparation method of a molybdenum selenide/oxygen defect bismuth oxybromide @ Jin Sanxiang Z-heterojunction photocatalyst, which adopts a hydrothermal-oleylamine reduction method to prepare a molybdenum selenide/oxygen defect bismuth oxybromide @ gold composite material, and improves the photocatalytic performance of bismuth oxybromide by in-situ reduction, high-temperature and high-pressure control of surface structure and morphology and introduction of surface defects, improves the catalytic activity of the catalyst, realizes the effective separation of photo-generated carriers of the catalyst, and simultaneously maintains the stronger redox capability of the photo-generated carriers. The invention also provides application of the molybdenum selenide/oxygen defect bismuth oxybromide @ Jin Sanxiang Z-type heterojunction photocatalyst. The first object of the invention is to provide a preparation method of molybdenum selenide/oxygen defect bismuth oxybromide@ Jin Sanxiang Z-type heterojunction photocatalyst, which comprises the following steps: (1) Preparing nano flower BiOBr-OVs: Dissolving bismuth nitrate pentahydrate and polyvinylpyrrolidone-K30 into a mixed solution of ethylene glycol and deionized water through ultrasonic treatment and stirring, adding potassium bromide into the solution, stirring the solution at room temperature, transferring the finally obtained transparent solution into a 50mL high-pressure reaction kettle for reaction, centrifuging after the reaction is finished to obtain a product, washing with water and ethanol, and vacuum-drying at 60-80 ℃ for 5-7h to obtain a flower-type BiOBr-OVs sample with surface oxygen defect modification; (2) Preparation of BiOBr-OVs@Au: Mixing oleylamine containing tetrachloroauric acid wi