A leaf-branch TiO2/carbon@MOF composite for selective CO2 photoreduction

Abstract Photocatalytic CO2 reduction provides a promising way for solving the energy crisis and environmental issues. Herein, a well-integrated photocatalyst is fabricated through growing leaf-like zeolitic imidazolate frameworks (ZIF-L) on branch-like titanium dioxide/carbon (TiO2/C) nanofiber for selective CO2 reduction. This platform enables the study of the synergistic effect of the photocatalytic performance, where the strong CO2 adsorption/activation, highly efficient light-harvesting, promoted electron-hole pairs separation, and specific metal Lewis sites are met by integrating suitable band matched ZIF and TiO2, as well as interfaced graphitic carbon. As a result, a largely increased CO generation rate of 28.6 μmol h−1 g−1 with remarkable selectivity of 99 % is achieved in the TiO2/C@ZnCo-ZIF-L without using sacrificial reagent. This work thus provides an insight into the rational construction of well-integrated composites to enhance photocatalytic performance via a well-balanced synergistic effect.