Branched multiphase TiO2 with enhanced photoelectrochemical water splitting activity

An efficient hierarchical structure, nano-branch containing anatase TiO2 nanofibers and rutile nanorods, was prepared via the combination of the electrospinning and hydrothermal processes. This novel configuration of TiO2 multiphase possessed higher surface area, roughness, and fill factors compared with each single phase component prepared in the same condition, which significantly enhanced its light absorption. Our experimental results showed that within the interface of multiphase TiO2, the heterojunction promoted the charge separation and improved the charge transfer rate, leading to higher efficiency for photoelectrochemical water splitting. The photocurrent density of the nano-branched TiO2 electrode could reach 0.95 mA/cm2, which was almost twice as large as that of the pristine TiO2 nanorod. Our work provides a simple and feasible routine to synthesize complex TiO2 nanoarchitectures, which lays a foundation for improving energy storage and conversion efficiency of TiO2-based photoelectrodes.