Surface Self-Transforming FeTi-LDH Overlayer in Fe 2 O 3 /Fe 2 TiO 5 Photoanode for Improved Water Oxidation.

Integrating hematite nanostructures with efficient layer double hydroxides (LDHs) is highly desirable to improve the photoelectrochemical (PEC) water oxidation performance. Here, an innovative and facile strategy is developed to fabricate the FeTi-LDH overlayer decorated Fe 2 O 3 /Fe 2 TiO 5 photoanode via a surface self-transformation induced by the co-treatment of hydrazine and NaOH at room temperature. Electrochemical measurements find that this favorable structure can not only facilitate the charge transfer/separation at the electrode/electrolyte interface but also accelerate the surface water oxidation kinetics. Consequently, the as-obtained Fe 2 O 3 /Fe 2 TiO 5 /LDH photoanode exhibits a remarkably increased photocurrent density of 3.54 mA cm -2 at 1.23 V versus reversible hydrogen electrode (RHE) accompanied by an obvious cathodic shift (≈140 mV) in the onset potential. This work opens up a new and effective pathway for the design of high-performance hematite photoanodes toward efficient PEC water oxidation.