Consequence of hot electron of Au and PbS shell thickness on photo‒electrochemical and catalytic activity of ZnO@Au@PbS nanorods for decomposition of toxic organic chemicals and Cr(VI) reduction by UV-to-near-infrared photon harvesting

Abstract

In this research work, we have synthesised ZnO@Au@PbS nanorods (NRs) with different shell thickness by a facile chemical method. On introduction of Au nanoparticles (NPs) and PbS shells, the defect emission of ZnO NRs quench and the charge separation process enriches. Under simulated solar light irradiance the photoconductivity and charge transfer efficiency also escalate with Au NPs and PbS shell along with enhancing photocatalytic degradation of organic contaminant. The excitation wavelength dependent catalytic activity confirmed the significant enrichment in photocatalytic activity owing to the synergistic influence of Au NPs and PbS coating on ZnO NRs. The effect of aqueous solution pH and PbS shell thickness on photocatalytic reduction of Cr (VI) has been also explored. The possible charge transfer mechanism during the photocatalytic activity of ZnO@Au@PbS NRs is also proposed and analysed. The catalytic activity, stability and recyclability results revealed that ZnO@Au@PbS NRs are highly favourable and reusable for the environmental remedies.