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

Au nanoparticles modified branched TiO 2 (Au/B-TiO 2 ) arrays were synthesized and the crystallization and morphology of the branches could be well controlled by simply altering the reaction times. The B-TiO 2 array composed of ultra-thin nanorod with thickness of ∼5 nm showed enhanced photoelectrochemical performances compared to TiO 2 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/cm 2 at 1.23 V vs RHE, which was much higher than that of B-TiO 2 and TiO 2 nanorod array due to enhanced light harvesting ability, enhanced carriers' density that resulted from the synergistic effect of branched structure of TiO 2 and SPR surface plasmon resonance (SPR) effect of Au nanoparticles. [ABSTRACT FROM AUTHOR]