Large-scale preparation of titania film for water splitting reaction

Nanocrystalline TiO₂ films are used for optical devices, gas sensors, catalysts, and biomaterials. In this work, large-area anatase films were deposited on titanium substrates via a simple HF-H₂O₂ solution approach. HF influenced the morphology, size, and hydrogen evolution rate (during water splitting) of the anatase film. Changes in the amount and chemical form of the Na₂S-Na₂SO₃ sacrificial reagent were measured by UV–visible spectroscopy in the presence of a prepared TiO₂ photocatalyst during the water-splitting reaction. A striking fluctuation in the concentration of HS⁻, which was attributed to its consumption by hole oxidation and regeneration from S₄²⁻ by electron scavengers, indicated that a photocatalytic cycle was established between reactant and intermediates.