Liquid Phase Deposition of Nickel-Doped ZnO Film with Enhanced Visible Light Photoelectrocatalytic Activity

Abstract

Metal element doping is an effective way to tune visible light absorption ability and improve the charge carrier separation efficiency of a semiconductor. Herein, we studied the visible light photoelectrocatalytic property of ZnO doped with nickel (Ni-ZnO). The Ni-ZnO film was prepared by using a liquid phase deposition technique. Scanning electron microscopy analysis and X-ray diffraction measurement indicated that the as-prepared Ni-ZnO film comprised of many prismatic wurtzite nanoparticles. X-ray photoelectron spectroscopy analysis indicated that Ni2+ entered the ZnO lattice. Cyclic voltammetric analysis confirmed that Ni2+ in the ZnO lattice was electroactive and a pair of Ni2+/Ni3+ redox waves were observed. UV-visible diffuse reflectance and photoluminescence spectra showed that doping of Ni in ZnO improved the visible light utilization and separation of photogenerated charge carriers. The Ni-ZnO film subsequently exhibited a higher photocurrent than the ZnO film. The photoelectrocatalytic activity of the Ni-ZnO film was evaluated by the degradation of tetracycline under visible light illumination. The degradation rate constant for tetracycline on Ni-ZnO film was found to be 1.65 times higher than that of ZnO film.