Template-free synthesis of Ta3N5 nanorod arrays for efficient photoelectrochemical water splitting

We report the template-free synthesis of Ta3N5 nanorod array films grown on Ta foil by a combination of a vapor-phase hydrothermal process and subsequent nitriding. The Ta3N5 nanorod array film modified with Co(OH)x when used as a photoanode in a photoelectrochemical cell for water splitting yields a stable photocurrent density of 2.8 mA cm(-2) at 1.23 VRHE under AM 1.5G simulated sunlight. The incident photon-to-current conversion efficiency at 480 nm is determined to be 37.8%.