Novel sol–gel synthesis of Mo-doped ZnO-NPs for photo-catalytic waste water treatment using the RhB dye as a model pollutant

Photo-catalytic wastewater treatment is one of the most environmentally friendly, sound and cost-effective technique but the challenge is to identify the most efficient photo-catalyst. After titanium dioxide, zinc oxide (ZnO) is the most extensively utilized and readily available photo-catalyst for treating wastewater. The need of the hour is to improve its catalytic degrading efficacy so that it may be used as a commercial photo-catalyst. In this study, pure and Molybdenum (Mo-1, 2 and 3%)-doped ZnO nanoparticles (NPs) were fabricated via facile and cost-effective chemical sol–gel method. The influence of dopant concentration on pure ZnO-NPs has been investigated by examining their structural, optical and chemical properties. Fabricated NPs were analyzed using a variety of advanced characterization techniques such as XRD, EDS, SEM, UV–Visible, FTIR and PL spectroscopy. The Mo-doped ZnO XRD patterns show a wurtzite hexagonal crystal structure. It was discovered that the crystallite size of Mo-doped ZnO is significantly smaller than that of pure ZnO and declines as the Mo concentration increases. The photo-catalytic activity of 2% Mo-doped ZnO in Rhodamine B (RhB) degradation was investigated. It was discovered that the degradation efficiency of RhB over Mo-doped ZnO rises up to 2% doping and subsequently declines as doping levels increase.