The effect of catalyst weight on the photocatalytic performance of ZnO-Ag nanocomposites prepared by flame pyrolysis method

ZnO is the most widely used as a catalyst material for photocatalytic application due to the suitable band gap energy and the chemical stability. It was reported by our previous study that the photocatalytic performance was significantly affected by the Ag content. In this study, ZnO-Ag nanocomposite materials have been successfully fabricated by flame pyrolysis and the effects of catalyst weight ranging from 2 to 10 mg on the photocatalytic performance were also investigated. Zinc acetate and silver nitrate were used as precursors for producing ZnO-Ag nanocomposites. The catalyst products, ZnO-Ag nanocomposite, were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). While, UV Vis spectrometry was used to measure the concentration of methylene blue (MB) before and after irradiations. Photocatalytic performances of nanocomposites were performed by evaluating the degradation of MB under UV and sunlight irradiations. The photocatalytic tests showed that the best performance was attained when the Ag content was 5 wt% and the weight of catalyst was as much as 10 mg after irradiation with sunlight, where the degradation rate of MB was 98% and the rate constant was 0.09/min.