The fabrication of ZnO–SiO2 (ZS) composite found to be a great challenge owing to the disadvantage of the recent method such as high temperature and multistep process. To this end, a new and rapid method for fabricating zinc oxide (ZnO) and ZS composite particles by the simple electrospray method was developed. Results from this method provide a free agglomeration and smaller particle size of ZS composite (compared with pure ZnO) with an increase in the applied voltage, which correlates with the charge repulsion within the particles. The presence of silica inhibited the ZnO particles and crystal growth. The XRD and FTIR spectra indicated that silica covered the ZnO particles. Smaller ZS molar ratio with higher applied voltage had a significant role in minimizing the agglomeration of particle production. This suggested a morphological control of the composite through electrospray. The results of the photocatalytic degradation of methylene blue (MB) in aqueous solution revealed that the presence of silica effectively inhibited the photocatalytic activity of ZnO particles in which the degradation rates of ZnO without and with silica were 85% and 63%, respectively. The effect of silica on the ultraviolet (UV) shielding property of ZnO particles also examined.
Keywords: ZnO–SiO2 composite; Electrospray synthesis; Morphology control; Photocatalysis; Degradation of methylene blue