Synergistic promotion of photoelectrochemical water splitting efficiency of TiO2 nanorod arrays by doping and surface modification

Fast surface charge recombination and poor light capturing capability are regarded as the two critical factors that hamper the photoelectrochemical (PEC) performance of photoanodes. In the present work, we employed N-doping as well as surface modification with plasmonic Au nanoparticles (NPs) for synergistic promotion of PEC efficiency of TiO2 nanorod arrays. The results revealed that that the light harvesting ability and surface charge separation efficiency of TiO2 are significantly enhanced by the synergistic effect of N doping and surface modification of plasmonic Au NPs. Correspondingly, the PEC efficiencies were increased by 7 and 3 times, as compared with those of the pristine TiO2 nanorod arrays and N doping TiO2 (N-TiO2) counterparts, respectively, and were superior to those of most TiO2-based photoanodes ever reported. The present work might give some insight into the rational design of advanced photoanodes with both high efficiency and stability for PEC water splitting.