Long and Well-Separated TiO2 Nanowire Arrays Decorated with Au Nanoparticles for Visible-Light-Driven Photoelectrochemical Water Splitting

Photoelectrodes based on TiO2 decorated with Au nanoparticles (NPs) (Au-TiO2) have attracted great attention for visible-light-driven photoelectrochemical (PEC) water splitting applications. Herein, we report a highly efficient visible-light-responsive photoanode composed of Au NPs decorated well-separated TiO2 nanowire (NW) arrays with a length up to over 9 μm. The photocurrent was found to be about 16 times higher than that of bare TiO2 NWs under visible-light illumination. Moreover, the photocurrent increased linearly with NW length, suggesting good charge dynamic properties and efficient utilization of the decorated Au NPs of the photoanode. These results indicate that the long and well-separated NW arrays have great potential for future development of PEC devices.