Conjugated Porous Polymers Based on BODIPY and BOPHY Dyes in Hybrid Heterojunctions for Artificial Photosynthesis

Abstract Developing highly efficient photocatalysts for artificial photosynthesis is one of the grand challenges in solar energy conversion. Among advanced photoactive materials, conjugated porous polymers (CPPs) possess a powerful combination of high surface areas, intrinsic porosity, cross‐linked nature, and fully π‐conjugated electronic systems. Here, based on these fascinating properties, organic–inorganic hybrid heterostructures composed of CPPs and TiO 2 for the photocatalytic CO 2 reduction and H 2 evolution from water are developed. The study is focused on CPPs based on the boron dipyrromethene (BODIPY) and boron pyrrol hydrazine (BOPHY) families of compounds. It is shown that hybrid photocatalysts are active for the conversion of CO 2 mainly into CH 4 and CO, with CH 4 production 4 times over the benchmark TiO 2 . Hydrogen evolution from water surpassed by 37.9‐times that of TiO 2 , reaching 200 mmol g cat −1 and photonic efficiency of 20.4% in the presence of Pt co‐catalyst (1 wt% Pt). Advanced photophysical studies, based on time‐resolved photoluminescence and transient absorption spectroscopy, reveal the creation of a type II heterojunction in the hybrids. The unique interfacial interaction between CPPs and TiO 2 results in longer carriers’ lifetimes and a higher driving force for electron transfer, opening the door to a new generation of photocatalysts for artificial photosynthesis.