Preparation And Photocatalytic Activity Of Modified Bismuth Oxyiodide

As a new photocatalyst,bismuth oxyhalide has special layered structure and strong visible light response.Among them,the band gap of BiOI is narrow,and its light absorption wavelength range almost covers all visible light.It has strong visible light response performance,which has attracted widespread attention.The main contents of this paper are as follows:(1)Magnetic BiOI catalyst,BiOI/MgAl-LDHs catalyst and magnetic BiOI/MgAl-LDHs catalyst were prepared by solvothermal method.After calcination of hydrotalcite at different temperatures,the calcined BiOI/MgAl-LDHs catalyst was prepared,and the best preparation conditions were explored.Research result shows that the treatment efficiency of the calcined catalyst for Malachite Green dye solution is lower than without calcined BiOI/MgAl-LDHs catalyst.Among them,magnetic BiOI/MgAl-LDHs catalyst has the best catalytic performance,the morphology is a flower ball with uniform gap size.The maximum absorption wavelength of visible light is 638 nm,and its photocatalytic performance is significantly improved compared with pure BiOI.(2)The optimum conditions for the treatment of malachite green dye solution with magnetic BiOI/MgAl-LDHs composite catalyst were studied by orthogonal experiment.Under the optimal treatment conditions,the chroma and COD removal rate of Malachite Green can reach 92.03% and 84.32% respectly.Concurrently,the recovery experiments show that the catalyst has high recovery value.(3)The reaction kinetics of magnetic BiOI/MgAl-LDHs composite catalyst treating for Malachite Green solution was studied.The results show that the heterogeneous photocatalytic oxidation of Malachite Green dye solution treating with magnetic BiOI/MgAl-LDHs composite catalyst accords with the first-order reaction kinetic model.