Rhenium-Metalated Polypyridine-Based Porous Polycarbazoles for Visible-Light CO₂ Photoreduction

Transformation of CO2 into valuable chemicals and especially fuels is deemed as a promising approach to reduce our dependence on fossil fuels and to alleviate climate change. Carbazole-based porous polymers bearing rhenium-metalated polypyridine functionalities were constructed via simple oxidative coupling reaction. These porous polymers are employed as heterogeneous supports for immobilization of catalytically active rhenium complexes and furthermore provide high CO2 adsorption capabilities and light absorption abilities, i.e., photosensitizing properties. Consequently, such rhenium-metalated microporous polycarbazole networks show high efficiencies for CO2 photoreduction upon visible-light irradiation, with a CO evolution rate up to 623 μmol g–1 h–1 and selectivity of 97.8%. The microporous solid photocatalyst shows enhanced stability and photocatalytic performance compared to the molecular catalysts during long-term use.