PlasmonicAu-TiO2/ZnOCore-Shell Nanorod Array Photoanode for Visible-Light-Driven Photoelectrochemical Water Splitting

A plasmonic Au-TiO2/ZnO core-shell nanorod array (NR) photoanode exhibits efficient photoelectrochemical water splitting induced by the plasmonic energy and typeII TiO2/ZnO heterojunction. The plasmonic Au-TiO2/ZnO core-shell NR photoanode provides a photocurrent density of 3.01 mAcm(-2) at 1.7V versus the reversible hydrogen electrode (RHE), almost 1.5 and 3 times higher than that of TiO2/ZnO core-shell NRs and TiO2 NRs upon exposure into simulated solar light. Moreover, the plasmonic Au-TiO2/ZnO core-shell NR photoanode shows a clear photocurrent density under visible-light irradiation (lambda>400 nm) with a photocurrent density of 0.11 mAcm(-2) at 1.23V vs. RHE. The visible-light-excited photocurrent is mainly caused by the surface plasmon resonance effects produced by plasmonic Au nanoparticles, which benefit the visible-light absorption and charge separation of the wide-band-gap TiO2/ZnO heterojunction through the electrons and resonant energy transfer. Additionally, the strong interfacial interaction between TiO2 and ZnO leads to an effective photoinduced interfacial charge separation and transfer.