Donor-acceptor-based conjugated polymers for photocatalytic energy conversion

Photocatalytic solar-to-chemical energy conversion is deemed to be a promising, eco-friendly, and low-energy input strategy for addressing the energy crisis. Donor−acceptor (D−A) conjugated polymers (CPs) have recently emerged as the hub in photocatalysis due to their charming properties, such as variable molecular structure, accessible functionalization, tunable electronic band structure, and versatile synthetic approaches. These features enable D−A-based CPs to be a potential alternative for conventional inorganic photocatalysts. Currently, researchers are making great efforts to design highly-efficient D−A-based CPs for adaptable photocatalytic reactions. In this review, the development, classification, and common synthetic strategies of D−A-based CPs are introduced. The recent progress of D−A-based CPs in photocatalytic energy conversion is systematically summarized, including photocatalytic H2 evolution, O2 evolution, overall water splitting, CO2 reduction, H2O2 production, and organic transformation. Meanwhile, the impacts of molecular/electronic structure and morphology of D−A-based CPs on light-harvesting capacity, exciton dissociation, and interfacial reaction during the photo-redox reactions are clarified. Finally, the conclusions and future challenges for photocatalytic energy conversion over D−A-based CPs are provided. This review is expected to offer an in-depth and comprehensive understanding of photocatalytic energy conversion in the aspect of mechanism, as well as to stimulate inspiration for designing D−A-based CP photocatalysts with surpassing efficiency.