Enhancement of Mass and Charge Transfer during Carbon Dioxide Photoreduction by Enhanced Surface Hydrophobicity without a Barrier Layer.

The CO 2 reduction reaction (CRR) represents a promising route for the clean utilization of renewable resources. But mass-transfer limitations seriously hinder the forward step. Enhancing the surface hydrophobicity by using polymers has been proved to be one of the most efficient strategies. However, as macromolecular organics, polymers on the surface hinder the transfer of charge carriers from catalysts to reactants. Herein, we describe an in-situ surface fluorination strategy to enhance the surface hydrophobicity of TiO 2 without a barrier layer of organics, thus facilitating the mass transfer of CO 2 to catalysts and charge transfer. With less obstruction to charge transfer, a higher CO 2, and lower H + surface concentration, the photocatalytic CRR generation rate of methanol (CH 3 OH) is greatly enhanced to up to 247.15 μmol g -1  h -1 . Furthermore, we investigated the overall defects; enhancing the surface hydrophobicity of catalysts provides a general and reliable method to improve the competitiveness of CRR.