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.