Branched TiO₂ Nanorod Arrays Decorated with Au Nanostructure for Plasmon-Enhanced Photoelectrochemical Water Splitting

Abstract

Photoelectrochemical (PEC) water splitting using semiconductors has become a promising strategy for clean and environmentally friendly solar fuel production. However, the efficiency of PEC water splitting is limited by the narrow optical absorption range, serious recombination of photogenerated charges and low quantum efficiency of semiconductors. Here we constructed a plasmonic photoelectrode by depositing Au nanoparticles (NPs) and Au nanorods (NRs) on the surface of three-dimensional (3D) branched TiO2 nanorod arrays. Experimental data indicate that the light absorption harvesting ability effectively enhanced in both ultraviolet and visible region by manipulating the shape of deposited Au nanostructure. Significantly, the photoconversion efficiency of Au NPs and Au NRs decorated 3D branched TiO2 photoanode increased by 2.6 times, compared with the pristine branched TiO2 nanorod arrays. Moreover, the plasmonic-enhanced PEC performance mechanism for water splitting is also discussed in this work.