SnO2 as thin conformal layer over BiVO4 surface for enhanced charge carrier separation towards O2 evolution from water oxidation

Recently, bismuth vanadate (BiVO₄) has attracted substantial attention for photocatalytic applications owing to its many advantages as semiconductor to drive water oxidation. Despite possessing promising characteristics to be applied in photocatalysis, the fast electron-hole pairs recombination is still one of the drawbacks involving this semiconductor. The use of conformal layers to minimize such limitation and to improve charge separation is the aim of this work. Herein, we report on the use of SnO₂ as a conformal coating layer over the BiVO₄ surface for O₂ evolution reaction. The incorporation of SnO₂ over the BiVO₄ surface showed the beneficial effect in O₂ evolution compared to the pristine material, resulting in 490 μmol after 6 h of irradiation. Transient absorption and surface photovoltage spectroscopies indicate enhanced charge carrier separation and transport by passivating BiVO₄ with SnO₂ thin layer. Even though the O₂ evolution tests in this work were carried out without the presence of a co-catalyst, the use of a thin conformal coating of SnO₂ over BiVO₄ showed promising results for further studies.