Highly Efficient Simultaneous Photocatalytic Reduction of CO 2 and O 2 from Air Using Conjugated Microporous Polymers with Ionic Imidazolium Sites

Efficient photocatalytic reduction of CO 2 is crucial to decrease the atmospheric concentration of CO 2 . Pairing this process with H 2 O 2 production is of considerable importance for simultaneously producing value‐added chemicals. However, the photocatalysts reported for such a process suffer from a high recombination rate of the surface/bulk charges, as well as inefficient enrichment and activation toward CO 2 and O 2 , resulting in low conversion efficiency even in the presence of organic sacrificial agents and expensive metal co‐catalysts. Herein, two 1,3,5‐triphenylbenzene‐based organic polymers with high ionic density and porosity are prepared through a facile Sonogashira polymerization. The ionic imidazolium sites embedded in the polymeric skeleton provide the two polymers (iCMP‐1 and iCMP‐2) with adsorptive selectivity for CO 2 /N 2 up to 98–102 at 273 K, facilitating the enrichment of CO 2 and O 2 molecules around the catalytic centers, thus boosting their catalytic conversion directly from air under solar light (100 mW cm −2 ). Benefiting from the improved charge separation and broad light absorption, along with high CO 2 and O 2 uptake, iCMP‐2 can deliver excellent CO and H 2 O 2 yields (611.8 and 810.6 μmol h −1 g −1 , respectively) under an atmosphere composed of water vapor and air without any co‐catalysts.