Enhanced photoelectrochemical oxidation of water over undoped and Ti-doped α-Fe2O3 electrodes by electrochemical reduction pretreatment

Abstract

We demonstrate that the photoelectrochemical oxidation of water over undoped and Ti-doped α-Fe₂O₃ electrodes could be highly enhanced by in situ electrochemical reduction pretreatment at −1.2 ≤ E < −0.6 V versus a saturated calomel electrode in the dark in aqueous 1 M NaOH electrolyte for tens of minutes. This enhancement is mainly due to a significant decrease of charge recombination and a favourable photohole transfer and is physically associated with the partial transformation of Fe₂O₃ to Fe₃O₄/FeOOH and Fe by electrochemical reduction.