Preparation Of BiOBr/Graphene And BiOBr/TiO 2 By Solvothermal Method And Their Photocatalytic Properties

Nowadays,there are a variety of environment issues in human's life,including:air pollution,water pollution,heavy metal pollution,plastic pollution,light pollution,etc.,covering the industrial,commercial,civil and the military.Therefore,it is urgent to manage environmental problems.In recent years,the photocatalytic degradation of organic dye technology has been received extensive attention.Bismuth-containing compound is environmentally friendly,cheap and thus become hot spot of photocatalytic development.Studies have shown that BiOBr has good photocatalytic activity,but small specific surface area,low separation efficiency electron-hole pair that made it to be improved.It is worth that through composite other materials to modified BiOBr.Paper introduces the synthesis of BiOBr/Graphene,BiOBr/TiO2,the research of these two types micro-structure,photocatalytic activity and action mechanism by X-ray diffractometry?XRD?,Scanning electron microscope?SEM?,Transmission.electron microscope?TEM?,Ultraviolet-visible diffuse reflectance spectra?Uv-vis?,Photoluminescence spectroscopy?PL?,etc.In this paper,the specific contents are as follows:?1?Graphite oxide?GO?prepared by a modified Hummer's method,then GO,Bi?NO₃?₃·5H₂O and KBr as raw materials synthesized BiOBr/Graphene composite photocatalyst by mixing one-step solvothermal method.The prepared samples were characterized by XRD,SEM,TEM,Uv-vis,PL,etc.Experimental results show that suitable synthetic conditions of BiOBr/Graphene:N,N-dimethylformamide?DMF?and Ethylene glycol?EG?were mixed solvent,graphene loading was 0.75%,source of bromine was KBr,synthesis time and temperature were 12h,160?,the photocatalytic degradation rate of Rhodamine B?RhB?was reached 96.36%under UV irradiation for 30min.Study on the photocatalytic mechanism by adding radical scavenger shown that throughout the whole degradation process,O2·-play a key role.?2?Bi?NO₃?₃·5H₂O,Cetyl trimethyl ammonium bromide?CTAB?and Tetrabutyl titanate?TBOT?as raw materials synthesized BiOBr/TiO2 composite photocatalyst by one-step solvothermal method.The prepared samples were characterized by XRD,SEM,TEM,Uv-vis,PL,etc.Experimental results show that suitable synthetic conditions of BiOBr/TiO2:absolute ethyl alcohol was single solvent,Bi?NO₃?₃·5H₂O concentration was 17.5mmol/L,Bi/Ti ratio was 1:1,synthesis temperature and time were 150?,10h,under visible light irradiation for 25min the photocatalytic degradation rate of RhB was reached 97.37%,the photocatalytic degradation rate of Methylene blue?MB?was reached 63.92%.It's photocatalytic properties without significantly reduce after five times repeating-experiment.Study on the photocatalytic mechanism by adding radical scavenger shown that throughout the whole degradation process,the rule is O2·->hVB+.and O2·-is the key.The innovation point is that used DMF and EG as mixed solvent to synthesize BiOBr/Graphene,another innovation point is that used absolute ethyl alcohol as single solvent,the sample has good degradation of RhB and MB under visible light.