Solar Photocatalytic and Self-Cleaning Performances of HoVO4 Doped ZnO

In this article we report preparation of 5 wt% HoVO4 doped ZnO via template-free hydrothermal process and investigated its photocatalytic activity against azo dyes Rhodamine-B (Rh-B), Trypan Blue (TB) and Acid Black 1 (AB 1) in solar light irradiation. The as prepared HoVO4 doped ZnO was characterised by X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Field emission Transmission electron microscopy (FE-TEM), Brunauer-Emmett-Teller (BET) surface area measurements, X-ray photoelectron spectroscopy (XPS), Diffused reflectance (DRS) and Photoluminescence (PL) spectroscopy. The SEM images clearly indicate the formation of nanoparticles in the range of 20-50 nm. BET surface area of the HoVO4-ZnO is 2 times that of ZnO. Higher activity of HoVO4-ZnO in natural sunlight may be due to higher visible light absorption of HoVO4ZnO when compared to undoped ZnO. The results suggested that HoVO4 doping on ZnO has great influence on the photocatalytic activity. The prepared photocatalyst HoVO4-ZnO possesses high stability and reusability without appreciable loss of catalytic activity up to four runs. Significant hydrophobicity of HoVO4-ZnO reveals its self cleaning property.