Sb-Doped SnO2 Nanorods Underlayer Effect to the α-Fe2 O3 Nanorods Sheathed with TiO2 for Enhanced Photoelectrochemical Water Splitting

Abstract

Here, a Sb-doped SnO₂ (ATO) nanorod underneath an α-Fe₂ O₃ nanorod sheathed with TiO₂ for photoelectrochemical (PEC) water splitting is reported. The experimental results, corroborated with theoretical analysis, demonstrate that the ATO nanorod underlayer effect on the α-Fe₂ O₃ nanorod sheathed with TiO₂ enhances the PEC water splitting performance. The growth of the well-defined ATO nanorods is reported as a conductive underlayer to improve α-Fe₂ O₃ PEC water oxidation performance. The α-Fe₂ O₃ nanorods grown on the ATO nanorods exhibit improved performance for PEC water oxidation compared to α-Fe₂ O₃ grown on flat fluorine-doped tin oxide glass. Furthermore, a simple and facile TiCl₄ chemical treatment further introduces TiO₂ passivation layer formation on the α-Fe₂ O₃ to reduce surface recombination. As a result, these unique nanostructures show dramatically improved photocurrent density (139% higher than that of the pure hematite nanorods).

Keywords: DFT calculations; Sb doping; SnO2 nanorods; photoelectrochemical water splitting; α-Fe2O3 nanorods.