Inverse opal structured Ag/TiO2 plasmonic photocatalyst prepared by pulsed current deposition and its enhanced visible light photocatalytic activity

Abstract

We developed a pulsed current deposition method to fabricate TiO₂ inverse opals with highly dispersed Ag nanoparticles (NPs) as a visible light driven plasmonic photocatalyst. It is observed that the incorporation of Ag NPs can significantly improve the photocatalytic activity of TiO₂ inverse opals in the visible light region. The sample with a deposition time of 45 s has the highest measured photocatalytic activity, and exceeds that of the Ag/TiO₂ inverse opals prepared by a photochemical reduction method. Such an enhancement is ascribed to the optimized localized surface plasmon resonance property of the Ag NPs, and excellent separation of the photoexcited electrons and Ag⁺ ions, resulting from the uniform Ag NPs produced by pulsed current deposition. The proposed mechanism is further confirmed by hydroxyl radical detection and electrochemical impedance spectroscopy analysis. Our study provides new insight into the design and preparation of advanced visible light photocatalytic materials.