A γ-Fe2O3-SiO2 composite was prepared by sol-gel method followed by calcination at 700 ℃ for 30 min starting from tetraethoxysilane and iron nitrate.Upon further coating with SiO2 and TiO2,a TiO2/SiO2/（γ-Fe2O3）-S...A γ-Fe2O3-SiO2 composite was prepared by sol-gel method followed by calcination at 700 ℃ for 30 min starting from tetraethoxysilane and iron nitrate.Upon further coating with SiO2 and TiO2,a TiO2/SiO2/（γ-Fe2O3）-SiO2 magnetic photocatalyst was obtained.XRD results show that Fe in the composite converts to the（γ-Fe2O3） phase up to a processing temperature of 700 ℃,and further increase in temperature results in the formation of the（α-Fe2O3） phase.The TiO2/SiO2/（γ-Fe2O3）-SiO2 samples obtained are monodisperse spherical particles with 200～250 nm diameter,well coated firstly by an amorphous SiO2 layer and then by an anatase TiO2 layer.The TiO2/SiO2/（γ-Fe2O3）-SiO2 particles retain their magnetic property well and show high activity for the photocatalytic degradation of salicylhydroxamic acid.展开更多
文摘A γ-Fe2O3-SiO2 composite was prepared by sol-gel method followed by calcination at 700 ℃ for 30 min starting from tetraethoxysilane and iron nitrate.Upon further coating with SiO2 and TiO2,a TiO2/SiO2/（γ-Fe2O3）-SiO2 magnetic photocatalyst was obtained.XRD results show that Fe in the composite converts to the（γ-Fe2O3） phase up to a processing temperature of 700 ℃,and further increase in temperature results in the formation of the（α-Fe2O3） phase.The TiO2/SiO2/（γ-Fe2O3）-SiO2 samples obtained are monodisperse spherical particles with 200～250 nm diameter,well coated firstly by an amorphous SiO2 layer and then by an anatase TiO2 layer.The TiO2/SiO2/（γ-Fe2O3）-SiO2 particles retain their magnetic property well and show high activity for the photocatalytic degradation of salicylhydroxamic acid.
