Hematite Films Decorated with Nanostructured Ferric Oxyhydroxide as Photoanodes for Efficient and Stable Photoelectrochemical Water Splitting

Abstract

Hematite photoanodes are decorated with nanostructured FeOOH by photoelectrodeposition. An obvious cathodic shift in the photocurrent onset potential is observed, while four‐times enhancement of photocurrent density enhancement is acheived with FeOOH present. This can be ascribed to the high reaction area for the structure and high electrocatalytic activity of nanostructured FeOOH, which increases the amount of photogenerated holes involved in the water oxidation reaction and accelerates the kinetics of water oxidation. Furthermore, the obtained Fe2O3/FeOOH photoanode achieves considerable O2 evolution rate (10.1 μmol h−1 cm−2) under AM 1.5 G illumination and is maintained for as long as 70 h. The Fe2O3/FeOOH films show visible light response, high photocurrent density, and long‐term stability, and they are well qualified photoanode materials and a promising candidate for photoelectrochemical water splitting.