Microstructure Modification Of Bismuth Based Semiconductors And Their Performances For Photocatalytic Organic Synthesis

Energy shortage and environmental pollution is the main threat of human beings.Solar energy has been used to fill the gap of insufficient resources in many fields on earth.Visible light photocatalytic technology is an effective strategy and has been widely used in the fields of energy,materials,environment and chemistry.It is expected to be suitable for the synthesis of imines by adjusting the microstructure of BiOBr/BiOI and changing its band gaps.Aniline was converted to imine by Bi OBr/BiOI series catalysts under visible light,among which BiOBr/BiOI-1/3 catalyst had the highest activity.The conversion of BiOBr/BiOI-1/3 heterojunction is up to 68.9%,which indicates that heterojunction is crucial factor to activity.Bismuth oxybromide samples were synthesized through different additives（CA-citric acid,PVP–polyvinylpyrrolidone,CTAB-cetyltrimethylammonium bromide）,and it was found that the photocatalytic activity of B-1.0C+P was the highest,which could reach 80.6%,confirming that the photocatalysts with the{110}facet of BiOBr as the main exposed surface was successfully prepared.Multiple characterization methods,including X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,X-ray photoelectron spectroscopy（XPS）,Brunauer-Emmett-Teller（BET）analysis,UV–vis diffuse reflectance spectroscopy（DRS）,photoluminescence（PL）spectroscopy and electrochemical impedance spectroscopy（EIS）,were applied to elucidate the origin of the excellent photoactivity.The vital factors of organic synthesis,such as solvents,bases,different catalysts of the same series,the amount of reactants and the derivatives of reactants,were changed by controlling the variables to further study the photocatalytic performance of organic synthesis.Meanwhile,the effects of different light intensity and wavelength on the photocatalytic activity were discussed.The activity of BiOBr/BiOI-1/3 and B-1.0C+P were stable after 5 cycles.In addition,·O₂^-,h⁺ and e^- were the main active substances of both different aminations.