Highly efficient hematite films via mid-/ex-situ Sn-doping for photoelectrochemical water oxidation

In this study, we report the facile fabrication of Sn-doped hematite film via mid-situ and ex-situ doping methods for efficient photoelectrochemical (PEC) performances. The morphology of Sn-doped Fe2O3 films was varied with Sn precursor in the mid-situ doping process. The addition of SnCl2 rendered a smooth-surfaced and well-distributed nanorod morphology, but SnCl4 gave a deformed nanorod structure covered with layered coalescence of SnO2 particles. The former demonstrated much higher photoelectrochemical performances as photoanodes than the latter. The photocurrent can be further improved by surface modification with SnCl4 through spin-coating method. The effects of Sn precursors on the morphology, surface characteristics and the PEC properties of the photoanodes are investigated.