Enhancing Iron(III) Oxide Photoelectrochemical Water Splitting Performance Using Defect Engineering and Heterostructure Construction.

Fe 2 O 3 is a promising semiconductor for photoelectrochemical (PEC) water decomposition. However, severe charge recombination problems limit its applications. In this study, a F-Fe 2 O 3- x /MoS 2 nanorod array photoanode was designed and prepared to facilitate charge separation. Detailed characterization and experimental results showed that F doping in Fe 2 O 3 regulated the electronic structure to improve the conductivity of Fe 2 O 3 and induced abundant oxygen vacancies to increase the carrier concentration and promote charge separation in bulk. In addition, the internal electric field between F-Fe 2 O 3- x and MoS 2 facilitated the qualitative transfer of the photogenerated charge, thus inhibiting their recombination. The synergistic effect between the oxygen vacancy and F-Fe 2 O 3- x /MoS 2 heterojunction significantly enhanced the PEC performance of Fe 2 O 3 . This study provides a universal strategy for designing other photoanode materials with high-efficiency charge separation.