Photocatalytic Activity Inhibition by ZnO-SiO2 Nanocomposites Synthesized by Sonochemical Method

Abstract

Here, ZnO particles and ZnO-SiO2nanocomposites synthesized by sonochemical method under continuous ultrasound irradiation were reported. For an hour ultrasound irradiated by ultrasonic horn at atmospheric condition, nanorods and spherical structures with crystalline sizes 33 and 17 nm were obtained for ZnO and ZnO-SiO2, respectively, revealed that silica inhibited the particles and crystal growth. FTIR analysis also indicated that silica covered the ZnO particles. In addition, photocatalytic activity was also inhibited by silica in which ZnO without and with silica had degradation rate 69% and 48%, respectively, to degrade methylene blue solution under direct sunlight irradiation for an hour. The addition of SiO2to ZnO gives an advantage in some application to avoid excessive degradation by controlling their photocatalytic activity.