Design Of Several Magnetic Graphene Photocatalysts And Their Applications In Photocatalytic Epoxidation

Graphene with features of large specific surface area,higher electrical conductivity and electron mobility,high light transmittance,strong mechanical strength and good thermal conductivity,etc.makes itself suitable as an excellent carrier to form composite materials,which has aroused researchers'extensive attention.The graphene-based composite materials exerting the synergistic effect between the two or the three can not only improve or avoid the insufficiency of the semiconductor to the visible light and the wide band gap,but also have the characteristics of fast conduction electrons and strong adsorption capacity.Therefore,graphene-based composite materials have been widely used in photocatalytic organic pollutant degradation,photolysis water hydrogen production energy and organic synthesis.Relatively speaking,there are not many studies on organic synthesis,especially in photocatalytic organic synthesis.Meanwhile,because their recovery is not very convenient,loading magnetic materials onto graphene is the easiest and most effective solution,which can not only be recycled multiple times,but also improve the stability of the catalyst.Thus,the magnetic graphene composites aremodified by means of microwave,hydrothermal,impregnation,etc.,by noble metal?Au,Ag?deposition and metal oxide?TiO₂,VO_x?transition metal to obtain a novel magnetic graphene-based ternary composite photocatalyst.The structure and morphology of the catalyst are studied by various characterization methods and used to photocatalyze the epoxidation of styrene under low temperature conditions.The main research contents are as follows:1.Preparation and Characterization of Precious Metal?Au/Ag?Loaded Fe₃O₄/RGO and Its Application in Photocatalytic Oxidation of StyreneDifferent loadings of Au/Fe₃O₄/RGO and Ag/Fe₃O₄/RGO composite photocata-lysts are synthesized by microwave assisted method,and then characterized by different characterization methods to study their structure and morphology.At the same time,The catalytic activity of the reaction is investigated by continuously changing and optimizing the reaction conditions,such as AuNPs or AgNPs loadings,solvent type,the amount of 3%HCl,H₂O₂/styrene molar ratio,reaction time,catalyst dosage,etc.for photocatalytic oxidation of H₂O₂ styrene epoxidation.2.Preparation and Characterization of TiO₂/Fe₃O₄/RGO Composite Photocata-lyst and Its Application in Photocatalytic Epoxidation of StyreneDifferent loadings of TiO₂/Fe₃O₄/RGO composite photocatalysts are synthesized by hydrothermal method,and then characterized by different characterization methods to study their structure and morphology.At the same time,The catalytic activity of the reaction is investigated by continuously changing and optimizing the reaction conditions,such as TiO₂ loadings,solvent type,the amount of 3%HCl,H₂O₂/styrene molar ratio,reaction time,catalyst dosage,etc.for photocatalytic oxidation of H₂O₂styrene epoxidation.3.Preparation and Characterization of VO_x/Fe₃O₄/RGO Composite Photocata-lyst and Its Application in Photocatalytic Oxidation of StyreneDifferent loadings of VO_x/Fe₃O₄/RGO composite photocatalysts are synthesized by impregnation method,and then characterized by different characterization methods to study their structure and morphology.At the same time,The catalytic activity of the reaction is investigated by continuously changing and optimizing the reaction conditions,such as VO_x loadings,solvent type,the amount of 3%HCl,H₂O₂/styrene molar ratio,reaction time,catalyst dosage,etc.for photocatalytic oxidation of H₂O₂styrene epoxidation.