Investigation of Photocatalytic Degradation of Methyl Orange by Using Nano-Sized ZnO Catalysts

Nano-sized ZnO catalysts were prepared by a direct precipitation method under the optimal conditions (calcination of precursors at 550 ̊C for 120 min). The as-synthesized ZnO catalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and UV-Vis spectroscopy. The photocatalytic properties of ZnO nanoparticles were investigated via methyl orange (MO) as a model organic compound under UV light irradiation. The influence of operating parameters on MO degradation including the amount of ZnO catalysts, pH value of solutions, and the photodegradation temperature was thoroughly examined. In addition, the kinetic process of photocatalytic degradation of MO using nano-sized ZnO catalyst was also examined, and the degradation of MO follow the first order kinetics.