Au nanoparticles modified branched TiO2 nanorod array arranged with ultrathin nanorods for enhanced photoelectrochemical water splitting

Abstract

Au nanoparticles modified branched TiO2 (Au/B-TiO2) arrays were synthesized and the crystallization and morphology of the branches could be well controlled by simply altering the reaction times. The B-TiO2 array composed of ultra-thin nanorod with thickness of ∼5 nm showed enhanced photoelectrochemical performances compared to TiO2 nanorod array due to decreased resistance and increased carriers' transfer efficiency. Further, after the modification of Au nanoparticles, the photocurrent density was ∼2.5 mA/cm2 at 1.23 V vs RHE, which was much higher than that of B-TiO2 and TiO2 nanorod array due to enhanced light harvesting ability, enhanced carriers' density that resulted from the synergistic effect of branched structure of TiO2 and SPR surface plasmon resonance (SPR) effect of Au nanoparticles.