Photocatalytic Activities of Cobalt-Doped ZnO Nanoparticles by Hydrothermal Method

Abstract

Photocatalytically active cobalt-doped ZnO (Co: ZnO) hexagonal nanoparticles have been prepared by hydrothermal process. X-ray diffraction, SEM, FTIR and UV–vis spectroscopy confirmed that the dopant ions substitute for some of the lattice zinc ions, and furthermore, that Co2+ ion exists. The as-prepared Co: ZnO samples have an extended light absorption range compared with pure ZnO and showed highly efficient photocatalytic activity, only requiring 120 min to decompose ~90% of MB dye under sun light irradiation. The results indicated that a strong electronic interaction between the Co and ZnO was present, and that the incorporation of Co promoted the charge separation and enhanced the charge transfer ability and, at the same time, effectively inhibited the recombination of photogenerated charge carriers in ZnO, resulting in high visible light photocatalytic activity.