In Situ Nanoimaging of Photoinduced Charge Separation at the Plasmonic Au Nanoparticle‐TiO₂ Interface

Photoinduced charge distributions for single Au nanoparticles deposited on single crystalline TiO2 are visualized in situ by Kelvin probe force microscopy. Under UV light, the electrons in excited TiO2 transfer to the Au nanoparticles. In contrast, when the Au nanoparticles are selectively excited by visible-infrared light, electrons are injected from the nanoparticles to TiO2, resulting in plasmon-induced charge separation.