Recent advances and perspective of modified TiO2-based photoanodes toward photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting is regarded among the best methods to combat current growing energy crisis and environmental pollution problems. Nevertheless, low solar-to-hydrogen (STH) efficiency of conversion keeps it under continuous research. Thus, researching materials with high photoelectric conversion efficiency and high stability is currently a priority. TiO2 is widely applied as a photocatalytic material with favorable stability and appropriate energy band. Considerable efforts have been devoted to suppressing electronhole complexation and promoting light absorption and carrier transport to obtain TiO2 with higher photocatalytic performance. We begin this review by describing the structure, properties and operational principles for PEC water splitting. The latest advances in TiO2 modification are subsequently summarized, mainly including structure design, bulk-phase doping, noble metal deposition, surface reduction and composite systems. Lastly, significant challenges and perspectives for developing TiO2 photoanodes for PEC water splitting are presented.