Cooperation of oxygen vacancies and 2D ultrathin structure promoting CO photoreduction performance of BiTiO.

Reduction of CO to solar fuels by artificial photosynthesis technology has attracted considerable attention. However, insufficient separation of charge carriers and weak CO adsorption hamper the photocatalytic CO reduction activity. Herein, we tackle these challenges by introducing oxygen vacancies (OVs) on the two-dimensional BiTiO ultrathin nanosheets via a combined hydrothermal and post-reduction process. Selective photodeposition experiment of Pt over BiTiO discloses that the ultrathin structure shortens the migration distance of photo-induced electrons from bulk to the surface, benefiting the fast participation in the CO reduction reaction. The introduction of OVs on ultrathin BiTiO nanosheets leads to enormous amelioration on surface state and electronic structure, thereby resulting in enhanced CO adsorption, photoabsorption and charge separation efficiency. The photocatalytic experiments uncover that ultrathin BiTiO nanosheets with OVs reveal a largely enhanced CO photoreduction activity for producing CO with a rate of 11.7 μmol g h in the gas-solid system, ~3.2 times higher than that of bulk BiTiO. This work not only yields efficient ultrathin photocatalysts with OVs, but also furthers our understanding on enhancing CO reduction via cooperative tactics.