Uncovering the potential of yttrium doped zinc oxide nanoparticles as an efficient catalyst for photodegradation of recalcitrant pollutant and a contributor antibacterial property

Abstract

This work focused on the development of photocatalytic and antibacterial ZnO doped nanoparticles for wastewater treatment application. ZnO nanoparticle was successfully doped via a sol-gel method with different concentration of yttrium (Y), a rare-earth element. The improved properties of the structural, optical, photocatalytic and antibacterial after the nanoparticles doping modification were analyzed. XRD analysis confirmed the hexagonal (wurtzite) structure with average crystalline size between 10 and 22.7 nm. The exhibited XRD peaks that shifted towards lower angles after doping confirmed the Y3+ substitution in the ZnO structures. High-resolution transmission electron microscopy (HRTEM) showed an increase in grain size as the concentration of Y3+ ions inside the ZnO matrix increased. Ultraviolet-visible-near-infrared spectroscopic measurement revealed a red shift of the bandgap energy of 0.128 eV, which confirmed the substitution process. It was observed that the Y-dopant significantly improved the photocatalytic activity of the ZnO nanoparticles; 91.8 %, 72.9 %, 29.2 % and 85.0 % of 20 ppm of humic acid, 20 ppm of BPA, 20 ppm of phenol and 20 ppm of caffeine respectively under UVA light irradiation. In addition, Y-doped ZnO nanoparticle was found to be highly effective against S. aureus as compared to E. coli. The 9 wt% Y-doped ZnO (9YZnO) nanoparticles have shown no bacterial growth at both minimum inhibitory concentration/minimum bacterial concentration MIC/MBC concentration which served as evidence of the improved antibacterial properties of the modified ZnO nanoparticles. Overall, in this study Y-doped ZnO nanoparticle had shown good performance as photocatalysis material in degrading organic compounds (natural, industrial and consumable organic compounds) and antibacterial material against germ positive microorganism. Considering the developed nanoparticle's performance, its application could be an efficient alternative for water and wastewater treatment applications.