Hypercrosslinked Polymers as a Photocatalytic Platform for Visible-Light-Driven CO2 Photoreduction Using H2O

The design of robust, high-performance photocatalysts is key for the success of solar fuel production via CO2conversion. Herein, we present hypercrosslinked polymer (HCP) photocatalysts for the selective reduction of CO2 to CO, combining excellent CO2 sorption capacities, good general stabilities, and low production costs. HCPs are active photocatalysts in the visible light range, significantly out-performing the benchmark material, TiO2 P25, using only sacrificial H2O. We hypothesise that superior H2O adsorption capacities led to concentration at photoactive sites, improving photocatalytic conversion rates when compared to sacrificial H2. These polymers are an intriguing set of organic photocatalysts, displaying no long-range order or extended pi-conjugation. The as-synthesised networks are the sole photocatalytic component, requiring no co-catalyst doping or photosensitiser, representing a highly versatile and exciting platform for solar-energy conversion.