Unraveling the Surface Reactivity of Pristine and Ti-Doped Hematite with Water.

Water adsorption and dissociation on undoped and Ti-doped hematite thin films were investigated using near-ambient pressure photoemission and DFT calculations. A fine understanding of doping effects is of prime importance in the framework of photoanode efficiency in aqueous conditions. By comparison to pure FeO surface, the Ti(2%)-FeO surface shows a lower hydroxylation level. We demonstrate that titanium induces wide structural modifications of the surface, preventing it from reaching full hydroxylation.