Visible‐Light‐Driven Plasmonic Photocatalysis Enhanced by Charge Accumulation

Abstract Plasmon‐induced charge separation (PICS) at the interface between a plasmonic material and semiconductor is employed to drive photocatalytic reactions for conversion and storage of solar energy. Most of the conventional photoelectrodes based on PICS have an n‐M type structure with an interface between n‐type semiconductor (typically TiO₂) and plasmonic metal (typically Au) nanoparticles. Here we develop n‐M‐p type photoelectrodes by coating the TiO₂/Au photoelectrode with Ni(OH)₂ or CrO_x, which can collect and store positive charges. Both of the photoelectrodes show efficient PICS under visible light and accumulate positive charges released from resonant Au nanoparticles. The accumulated charges can be used for oxidation of organic species such as ethanol in the dark. The TiO₂/AuNP/Ni(OH)₂ photoelectrode exhibits an oxygen evolution ability under visible light with a certain bias voltage.