Construction of a Visible Light Z-scheme Photocatalyst: Curcumin Functionalized Cu2O/Ag Nanocomposites

Abstract

A stage-wise green synthesis protocol was used to prepare curcumin functionalized Cu2O/Ag nanocomposites. In this procedure, curcumin was used to reduce and functionalize Ag nanostructures on needle-shaped Cu2O nanoparticles. The prepared nanoparticles were found to be efficient visible-light photocatalysts for aqueous medium aerobic methyl orange (MO) degradation. Photocatalytic experiments in the presence of appropriate scavenger molecules showed that superoxide radicals were primarily responsible for MO degradation. Furthermore, the increase in the amount of Ag connecting the Cu2O and curcumin parts enhanced the recyclability of the photocatalyst. A Z-scheme mechanism concentrates the electrons in the LUMO of curcumin, and holes in the valence band (VB) of the Cu2O. While the electrons in the curcumin reduced oxygen to produce superoxide radicals, the Cu2O VB holes oxidized water to sustain the process. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim