Surface Self‐Transforming FeTi‐LDH Overlayer in Fe2O3/Fe2TiO5 Photoanode for Improved Water Oxidation

Abstract

AbstractIntegrating 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 Fe2O3/Fe2TiO5 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 Fe2O3/Fe2TiO5/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.