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

Recently, bismuth vanadate (BiVO 4) 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 SnO 2 as a conformal coating layer over the BiVO 4 surface for O 2 evolution reaction. The incorporation of SnO 2 over the BiVO 4 surface showed the beneficial effect in O 2 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 BiVO 4 with SnO 2 thin layer. Even though the O 2 evolution tests in this work were carried out without the presence of a co-catalyst, the use of a thin conformal coating of SnO 2 over BiVO 4 showed promising results for further studies. [Display omitted] • BiVO 4 @SnO 2 increased the amount of O 2 from 69 to 490 μmol after 6 h of irradiation. • The presence of SnO 2 protected BiVO 4 against charge carrier recombination. • SPS and TAS measurements confirm better charge carrier separation. [ABSTRACT FROM AUTHOR]