Enhancement of Plasmon-Induced Photoelectrocatalytic Water Oxidation over Au/TiO 2 with Lithium Intercalation

Plasmon-induced chemical reaction is an emerging field but its development faces huge challenges because of low quantum efficiency. Herein, we report that the solar energy conversion efficiency of Au/TiO in plasmon-induced water oxidation is greatly enhanced by intercalating Li into TiO . An incident photon-to-current efficiency as high as 2.0 %@520 nm is achieved by Au/Li TiO in photoelectrocatalytic water oxidation, realizing a 33-fold enhancement in photocurrent density compared with Au/TiO . The superior photoelectrocatalytic performance is mainly ascribed to the enhanced electric conductivity and higher catalytic activity of Li TiO . Furthermore, the ultrafast transient absorption spectroscopy suggests that lithium intercalation into TiO could change the dynamics of hot electron relaxation in Au nanoparticles. This work demonstrates that intercalation of alkaline ions into semiconductors can promote the charge separation efficiency of the plasmonic effect of Au/TiO .