Sn Doping into Hematite Nanorods for High-Performance Photoelectrochemical Water Splitting

Photoelectrochemical water splitting is of great attention due to its environmental friendly generation of clean fuels. Hematite (alpha-Fe2O3) is considered one of the promising candidates due to its intrinsic properties for the high performance photoelectrochemical electrode such as favourable bandgap (2.0-2.2 eV), a suitable energy band position, non-toxicity, low cost, and excellent chemical stability. Herein, we report about Sn-doped hematite nanorods and their implementation as photoanodes for photoelectrochemical water splitting. We provide the simple but efficient route to incorporate the Sn into the hematite without structural damage in the nanostructure and scrutinize the effect of Sn dopant on the photoelectrochemical activity of the hematite. By the two-step heat-treatment process, Sn can be successfully incorporated into the hematite, which reveals the enhanced photoelectrochemical responses compared with undoped hematite. We elaborate the effect of Sn dopant in the hematite on the photoelectrochemical activities, thereby the optimum concentration of Sn dopant can be suggested. In addition, the catalyst layer of the cobalt phosphate is introduced to further increase the photoelectrochemical performance of Sn-doped hematite nanorods. (C) 2019 The Electrochemical Society.