Plasmon-Enhanced Photocurrent using Gold Nanoparticles on a Three-Dimensional TiO₂ Nanowire-Web Electrode

In this study, an anatase/rutile mixed-phase titanium dioxide (TiO₂) hierarchical network deposited with Au nanoparticles (Au/TiO₂ ARHN) was synthesized using a facile hydrothermal method followed by a simple calcination step. Such a unique structure was designed for improving the light harvest, charge transportation/separation, and the performance of photo-electro-chemical (PEC) cells. The properties of the as-synthesized Au/TiO₂ ARHN in PEC cells were investigated by electrochemical measurements using a three-electrode system in a 1 M NaOH electrolyte. Remarkably, a 4.5-folds enhancement of the photocurrent for Au/TiO₂ ARHN was observed as compared to that for TiO₂ nanowire (NW), under AM1.5G solar illumination, suggesting its potential application in PEC cells. A mechanism has been proposed to explain the high photocurrent of Au/TiO₂ ARHN in PEC water splitting.