Hydrothermal growth of Sn4+-doped FeS2 cubes on FTO substrates and its photoelectrochemical properties

Sn4+-doped FeS2 cubes with high yield thin films have been successfully synthesized on FTO glass through a simple hydrothermal process. The Sn4+-doped FeS2 cubes are single crystalline in cubic structure with (2 0 0) facet as the main exposed surface. The formation process was investigated. Sn2+ was found to play an important role during the formation process of FeS2 growing on FTO glass. The direct optical band gap value can be estimated to be 1.71 eV which is much larger than that of bulk FeS2 due to the Sn4+ doping. The photoelectrochemical properties of the Sn4+-doped FeS2 films were studied as well. There is a significant increase in photocurrent of Sn4+-doped FeS2 electrode compared to that of undoped sample.

► We successfully grew Sn4+-doped FeS2 thin films on FTO glass through a simple hydrothermal process.
► Sn2+ was found to play an important role during the formation process of Sn4+-doped FeS2 growing on FTO glass.
► The Sn4+-doped FeS2 films have a promising band gap of about 1.71 eV.
► Sn4+-doped FeS2 films exhibited much better photoelectric performance compared to that of the undoped sample.