Synthesis and high photocatalytic activity of Eu-doped ZnO nanoparticles

Pure ZnO and Eu-doped ZnO nanoparticles (NPs) with different amounts of Eu were prepared using a simple precipitation method. The as-synthesized photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), UV–vis diffuse reflectance spectroscopy (DRS), inductively coupled plasma (ICP), X-ray photoelectron spectroscopy (XPS), fluorescence spectroscopy and N2 adsorption–desorption isotherms. The activity of the as-prepared photocatalysts was evaluated based on the photodegradation of methyl orange (MO) under UV light. The 1.0 mol% Eu-doped ZnO NPs exhibited the best photocatalytic activity. The effects of photocatalyst loading, the initial dye concentration and pH values on the photodegradation efficiency were studied using the 1.0 mol% Eu-doped ZnO photocatalyst, and the optimum conditions were determined. In addition, the Eu-doped ZnO NPs were easily recovered and reused.