Design and application of hierarchical α-Fe2O3/In2O3 heterojunction photoanode for enhanced photoelectrochemical water oxidation

alpha-Fe2O3 attracted great attention as a promising photoanode candidate for photoelectrochemical (PEC) H2O spitting. In this paper, one dimensional (1D) alpha-Fe2O3 nanorods coupled 2D porous In2O3 nanosheet assemblies were designed to construct a S-scheme alpha-Fe2O3/In2O3 heterojunction photoanode. The unique porous In2O3 nanosheet assemblies are conductive to improve light-harvesting efficiency and provide more active sites. An internal electric field induced at the alpha-Fe2O3/In2O3 heterojunction interface could promote interfacial charge separation and transfer, enhancing redox kinetics. The as-obtained 2D/1D In2O3/alpha-Fe2O3 photoanode achieved a stable photocurrent density of 2.2 mA cm(-2) at 1.23 V (vs. RHE). It is 6.3 times higher than that of the alpha-Fe2O3 component, and got a max applied bias photo-to-current efficiency (ABPE) of 0.28%, which is about 5.8 times that of bare alpha-Fe2O3 at 1.01 V. The work provides a promising strategy to construct high-performance S-scheme heterostructure photoanodes, featuring the role of surface and interface science in sustainable energy.