Preparation method of BiOBr/AgBr/GO ternary composite photocatalyst

Abstract

The invention discloses a preparation method of a BiOBr / AgBr / GO ternary composite photocatalyst and belongs to the field of inorganic catalysis materials. According to the preparation method disclosedby the invention, graphene oxide GO is prepared firstly and the GO and AgBr are compounded on the surface of BiOBr through a one-step precipitation method to form a ternary compound; the preparationmethod has the advantages of simple preparation technology, convenience for operation and very good practicability. According to the preparation method disclosed by the invention, a heterojunction isformed by the BiOBr and the AgBr, and the GO has good electrical conductivity so that photoelectrons move rapidly and the compounding of electron hole pairs is inhibited, and furthermore, the photocatalytic activity of the BiOBr is effectively improved; the degradation efficiency of the prepared ternary composite photocatalyst on Rhodamine B reaches 96 percent within 16min; the degradation efficiency on the Rhodamine B under the same condition still reaches 90 percent after the ternary composite photocatalyst is recycled and used for three times. The product prepared by the preparation methodcan be widely applied to photocatalytic degradation of organic pollutants in wastewater.

Description

technical field [0001] The invention relates to a preparation method of a BiOBr / AgBr / GO ternary composite photocatalyst, belonging to the technical field of inorganic photocatalytic materials. Background technique [0002] Semiconductor photocatalytic materials have obvious advantages in catalyzing the photodegradation of organic pollutants in industrial sewage. It has the characteristics of energy saving, no secondary pollution, and complete removal of pollutants. The layered structure of p-type semiconductor bismuth oxyhalide (BiOX, X=Cl, Br, l) can promote the transfer of photogenerated carriers in the photocatalytic process and improve the quantum efficiency of photoelectrons, especially the suitable band gap of BiOBr makes it suitable for The absorption rate of visible light is higher and has better photocatalytic activity. Studies have shown that O in the valence band of BiOBr 2P The orbital absorbs less photons, and the bandgap width is 2.91eV, resulting in low util...

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Problems solved by technology

[0004] Existing research on the modification of BiOBr by semiconductor compounding, such as "Unusual reactivity of visible-light-responsive AgBr-BiOBr heterojunction photocatalysts" in "Journal of Catalysis" No. 18, No. 18, 2012, pages 116-125 (comparison file 1 ), first Bi(NO 3 ) 3 ·5H 2 O and AgNO 3 Dissolved in acetic acid, then add NaBr to obtain composite photocatalyst by co-precipitation method, this method has the following disadvantages: (1) AgBr is prone to agglomeration, so that AgBr is dispersed unevenly on the surface of BiOBr; The activity is not significantly improved, and the bandgap width of the prepared composite catalyst is 2.88eV

In recent years, the research work on BiOBr ternary doped or loaded composite photocatalysts has gradually increased. The existing preparation methods of BiOBr composite photocatalysts, such as: "Hierarchical core- shell SiO 2 @PDA@BiOBr microspheres with enhanced visible-light-driven photocatalytic performance” (comparison file 2), preparing SiO by sol-gel method 2 @PDA, SiO by solvothermal method 2 Composite @PDA and bismuth oxybromide raw materials to prepare SiO 2 and the BiOBr composite material modified by PDA (polydopaan), the method has the following disadvantages: (1) the catalytic performance of each component is low, and it takes 100min to degrade 200mL of RhB with a concentration of 15mg / L; (2) using a solvent Thermal method, using organic solvents, has the disadvantages of high energy consumption and high cost

This method has the following disadvantages: (1) the cost of preparing the catalyst by the hydrothermal method is relatively high, and the preparation process is complicated and time-consuming; (2) the activity of the product is low, and it takes 90 minutes to degrade 10 mL of RhB with a concentration of 10 mg / L

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