Preparation and Photocatalytic Performance of Porous ZnO Micron Powders

Abstract

Porous ZnO micron powders are obtained by thermal oxidation in air. The as-obtained powders are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption, and ultraviolet-visible spectrophotometer, and the photocatalytic degradation of methyl orange (MO) is evaluated. The results indicate that, with the increase in thermal oxidation temperature, the nanoparticles on the surface of porous ZnO gradually grow and connect to each other, and the porous structure is destroyed, which results in the decrease in the specific surface area. Porous ZnO obtained at 800°C exhibits the best photocatalytic performance for MO degradation. The highest degradation rate is 0.043 min⁻¹ using 10 mg of the ZnO powders and 10 mg L⁻¹ of the MO solution.