Visible light enhanced p-nitrophenol reduction by glycerol over Ag/Cu core-shell bimetallic nanocatalysts

Abstract

Investigations on photocatalytic properties of core-shell nanostructures of plasmonic noble metals are scarce in the scientific literature. The research in this communication investigates the photocatalytic properties of Cu@Ag and Ag@Cu core-shell nanostructures. These were prepared by a green methodology using ethylene glycol as the solvent and the reductant. The reaction catalyzed on these nanostructures was the p-nitrophenol reduction by glycerol (a green reductant) to p-aminophenol. The reaction was carried out in the dark as well as under visible light. While these nanostructures catalyzed this reaction even in the dark, irradiation by visible light significantly boosted the reaction kinetics. Between the two, the Cu@Ag nanoparticles exhibited considerably enhanced plasmonic photocatalytic activity. Density functional theory (DFT) calculations revealed the ground state electronic structure of the core-shell nanostructure. Photo-excited states, simulated by time-dependent density functional theory (TD-DFT) calculations, were used to get an understanding of the mechanism followed. © 2021 Elsevier Ltd. All rights reserved.