Photocatalytic water oxidation with a Prussian blue modified brown TiO₂

A recently emerging visible light-absorbing semiconductor, brown TiO₂ (b-TiO₂), was coupled with a CoFe Prussian blue (PB) analogue to prepare an entirely earth-abundant semiconductor/water oxidation catalyst hybrid assembly. PB/b-TiO₂ exhibits a sevenfold higher photocatalytic water oxidation activity compared to b-TiO₂. An elegant band alignment unified with the optical absorption of b-TiO₂ and excellent electronic dynamics of PB yield a high-performance photocatalytic system.