Photocatalytic activities of ZnO-based materials: effect of rare-earth metal ion loading

Abstract

In this study, pure and rare earth metal loaded ZnO photocatalytic materials have been prepared by coprecipitation method using the precursors of zinc and metal ions. These materials have been characterized by using scanning electron microscopy in combination with energy dispersive X-ray (SEM-EDAX) spectroscopy, X-ray diffractometer (XRD), surface area analyzer (BET) and atomic force microscopy (AFM). Photocatalytic activities of the synthesized catalysts has been evaluated for the decolorization of methyl orange (MO) dye under UV light. The effects of some parameters such as catalyst loading, initial MO concentration, pH value, and the amount of metal loading on the decolorization efficiency were discussed. The highest performances were obtained with the lowest metal content catalyst at pH 8. MO photodecolorization obeyed pseudo first order kinetics. Also, Langmuir-Hinshelwood model was applied. A mechanism was postulated for the decolorization process of MO.