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 HoVO₄– ZnO 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.