Abstract: ZnO-SiO2 composite photocatalysts were prepared by a facile sol-gel process.The effect of heating rate and deposition process on structure, morphology and photocatalytic activity of ZnO-SiO2 was studied.Products were characterized by X-ray diffraction, N2 adsorption-desorption techniques, scanning electron microscopy, UV-Vis diffuse reflectance spectra and photoluminescence.Rhodamine B was used as model dye to evaluate the photocatalytic activity of ZnO-SiO2 composite photocatalysts.The results show that the heating rate has greatly impact on photocatalytic activity of ZnO-SiO2.Scanning electron microscopy images show uniform deposition of zinc oxide nanoparticles on the surface of silica spheres.When the weight ratio of ZnO to SiO2 is 1∶1, the highest photodegradation rate is found.

Key words: ZnO-SiO2 composite photocatalysts were prepared by a facile sol-gel process.The effect of heating rate and deposition process on structure, morphology and photocatalytic activity of ZnO-SiO2 was studied.Products were characterized by X-ray diffraction, N2 adsorption-desorption techniques, scanning electron microscopy, UV-Vis diffuse reflectance spectra and photoluminescence.Rhodamine B was used as model dye to evaluate the photocatalytic activity of ZnO-SiO2 composite photocatalysts.The results show that the heating rate has greatly impact on photocatalytic activity of ZnO-SiO2.Scanning electron microscopy images show uniform deposition of zinc oxide nanoparticles on the surface of silica spheres.When the weight ratio of ZnO to SiO2 is 1∶1, the highest photodegradation rate is found.