Research On The Prepartion Of TiO₂-based Nanocomposites And Their Photoelectrocatalytic Performance

Core-shell nanoparticles SiO₂@TiO₂ and Fe₃O₄@TiO₂ nanomaterials were successfully prepared by the hydrothermal method,the performance of SiO₂@TiO₂ on the photocatalytic degradation of rhodamine B（RhB）were investigated.and then the preparation conditions were optimized.The effects of TBOT amount,HPC amount,reaction time,reaction temperature and water content on the catalytic performance of SiO₂@TiO₂ on the photocatalytic degradation of rhodamine B were investigated.The core-shell TiO₂@Si O₂ composite on a single reduced grapheneoxide（RGO）sheet by using UV-assisted photocatalytic reduction,the effect of the graphene load on the catalytic performance of SiO₂@TiO₂/RGO on the photocatalytic degradation of rhodamine B was investigated.The Fe₃O₄@TiO₂ nanoparticles were prepared by hydrothermal synthesis method,and the effects of TBOT amount,the amount of ammonia,reaction temperature and reaction time on the photocatalytic efficiency were investigated.The preparation process of Fe₃O₄@TiO₂ nanoparticles was optimized.The physicochemical properties of core-shell nanoparticles were characterized by scanning electron microscopy（SEM）,X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FT-IR）and X-ray energy dispersive spectrometer（EDS）.The main content and results showed that:（1）the optimized preparation conditions of SiO₂@TiO₂ material was TBOT dosage of 1.0m L,HPC amount of 1.0 mL,water content of 0.02 g and reaction time of 80 min,reaction temperature of 50 ℃.The crystal structure of TiO₂ was the mixture of anatase and rutile phase.The specific surface area of SiO₂@TiO₂ material was 118.62m2/g.The particle size of TiO₂ coated onto SiO₂ surface was 12.4 nm.The core-shell structured of SiO₂@TiO₂ material can highly improve the photocatalytic activity and the degradation was 94.5%.（2）the graphene load for 1/0.05 is the best condition and the Ti-O-Si bond was stable combined,showing excellent synergistic effect with SiO₂@TiO₂,the photocatalytic degradation of RhB is 94.5%,the morphology of the nanoparticles was uniform,the sructure of the TiO₂ has no significantly change after the load.（3）The micromorphology of Fe₃O₄@TiO₂ nanoparticles prepared by hydrothermal synthesis method was irregular spheres structure,and the main components were Fe,Ti,O and C.（4）The optimized preparation conditions were TBOT amount of 1mL,ammonia amount of 0.3m L,reaction temperature of 85℃,reaction time of 4h.A fter loading,the Fe₃O₄@TiO₂ nanoparticles are magnetic and convenient for recycling.