Photocatalytic degradation-based efficient elimination of pesticides using ruthenium/gold metal nanoparticle-anchored zirconium dioxide

Abstract

Ruthenium and gold metal nanoparticles-incorporated zirconium dioxide (ZrO₂@Ru and ZrO₂@Au) nanostructures were developed as promising photocatalysts for wastewater remediation. These nanostructures were synthesized using a hydrothermal method and were well characterized with several techniques. ZrO₂ exhibited a nanoflower-like morphology while spherically-formed Ru/Au NPs were individually incorporated on the ZrO₂ surface in ZrO₂@Ru and ZrO₂@Au nanocomposites. The photocatalytic performance of ZrO₂@Ru and ZrO₂@Au was investigated for the degradation of diuron (DI) and methyl parathion (MP) pesticides. Both nanostructures exhibited remarkable photocatalytic activity under visible light exposure. For instance, ZrO₂@Ru displayed high efficiency for the degradation of DI and MP in 13 and 35 min, with an estimated rate constant of 0.2506 and 0.0762 min⁻¹, respectively. Similarly, the ZrO₂@Au nanostructure attained a rate constant of 0.1766 and 0.0456 min⁻¹ with a degradation time of 18 and 60 min for the degradation of DI and MP, respectively. Furthermore, the reactive species scavenger study and mass spectroscopy analyses were conducted to illustrate the photocatalytic degradation mechanism. Pesticide degradation was primarily governed by hydroxyl radicals via an oxidative pathway. In addition, the reusability of ZrO₂@Ru was validated, which reveals their immense capability for the degradation of toxic substances for environmental indemnity.