Plasmon resonance-based study of the peroxidaselike catalytic effect of gold nanoparticles

Abstract

In this paper, the peroxidaselike catalytic effect of gold nanoparticles (AuNPs) was explored in dye wastewater treatment by visible light excitation. Using hydrogen peroxide as a substrate, the peroxidaselike reaction was evaluated with AuNPs catalyzing the substrate oxidative degradation of the organic dye rhodamine B (RhB). The synthesized AuNPs were characterized by transmission electron microscopy. The degradation of RhB was observed by a UV-visible spectrophotometer. The results showed that under visible light irradiation, the AuNPs exhibited good peroxidaselike catalytic activity for the oxidative degradation of RhB by hydrogen peroxide. By studying the light wavelength and light intensity-dependent reaction rates, radical trapping, and hole acceptor incorporation, it was found that AuNPs can absorb photon energy and generate hot electrons through a localized surface plasmon resonance effect under light irradiation. Subsequently, hot electrons flow into the molecular orbitals of H2O2 based on energy matching, activating the molecule and transforming it into the transition state, which is proceeded by breakdown to release hydroxyl radicals (⋅OH) for oxidative destruction of RhB.