Boosting the photoelectrochemical water splitting of Fe2O3 by surface-state regulation

Abstract

Solving the issues of interface defects and carrier recombination in Fe₂O₃ photoanodes is of great significance for enhancing their photoelectrochemical water splitting performance. Herein, a semiconductor material, MoO₃, was incorporated in Fe₂O₃ nanorods as a composite photoanode. Compared to pristine Fe₂O₃, the Fe₂O₃/MoO₃-350 photoanode achieved a 3.2-fold increase in photocurrent density by varying the number of impregnations, reaching 1.09 mA cm⁻² at a bias of 1.23 V_RHE under 100 mW cm⁻² illumination. In the PEC water splitting reaction, the Fe₂O₃/MoO₃-350 photoanode exhibited significantly improved H₂ and O₂ production rates. The experimental results showed that the change in surface state distribution and the positively shifted surface state distribution (N_ss) center induced by the introduction of MoO₃ promoted the transfer of photogenerated charges and the kinetics of interfacial water oxidation. Therefore, this study contributes to an in-depth understanding of the influence of interfacial structural regulation on the surface-state distribution and provides a reference for the rational design of photoanode materials.