Highly enhanced dye sensitized photocatalytic oxidation of arsenite over TiO2 under visible light by I− as an electron relay

A highly efficient, regenerated and stable dye-sensitized photocatalytic system for the pre-oxidation of As(III) over nanostructured TiO2 films to less toxic As(V) under visible light (λ ≥ 420 nm) using ruthenium dye as a model sensitizer and I− as an electron mediator is reported. The oxidation rate could be greatly enhanced by I− especially for low concentrations of As(III).

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Efficient visible light dye-sensitized catalytic oxidation of As(III) is reported. ► The oxidation rate could be greatly enhanced by I– as an electron relay. ► The system is in situ regenerated and stable.