Manipulation of surface plasmon resonance of sputtered gold-nanoparticles on TiO2 nanostructured films for enhanced photoelectrochemical water splitting efficiency

Plasmonic solar water splitting is a promising way to realize the persistent supply of green energy in a sustainable manner. Here we report a largely enhanced performance of photoelectrochemical photoanodes by introducing Au nanoparticles (NPs) decoration onto the hydrothermal process grown TiO2 nanowires (NWs). Through a simple one-step sputtering process, dense and homogeneously separated Au NPs were prepared on TiO2 NWs. Compared to pristine TiO2 electrode, 10 nm Au decorated TiO2 electrode achieved >3 and 4 times photocurrent density enhancement measured under AM 1.5G and visible light illumination, respectively. The enhancement mechanism induced by localized surface plasmonic resonance effect is analyzed by the relative band and Fermi energy of corresponding materials.