Rapid formation of black titania photoanodes: pulsed laser-induced oxygen release and enhanced solar water splitting efficiency

Abstract

Solar energy is a key part of creating a sustainable society. Pulsed ultraviolet laser irradiation of titania films is a simple process for making oxygen-deficient black titania (TiO_2−x) films that use the solar spectrum efficiently. TiO_2−x photoanodes were obtained by KrF laser irradiation under low-vacuum conditions for several minutes. The TiO_2−x film had a larger absorbance than pristine TiO₂ in the visible light region, and it exhibited a substantial increase in photoelectrochemical water splitting under simulated solar light. The solar-to-hydrogen efficiency of the TiO_2−x photoanode reached 0.52%, which was 2.6-fold higher than that of the pristine TiO₂ photoanode. This rapid fabrication process for black titania photoanodes has great potential for industrial solar hydrogen production.