Structure-oriented optimization of hierarchical porous conjugated polymers for enhanced PET-RAFT polymerization

Hierarchically porous materials are highly valued for their large surface areas and tunable pore architectures, making them promising heterogeneous catalysts for photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization. However, the specific influence of pore structure on catalytic performance remains poorly understood. In this study, hierarchically porous conjugated organic polymers (COPs) were synthesized using a silica hard-template method and employed as photocatalysts for PET-RAFT polymerization. Under white LED light irradiation, the effects of template size and concentration on pore structure and photocatalytic performance were systematically investigated. Notably, a silica template with a concentration of 60 mg/mL and a particle size of 300 nm produced a COP with an average pore size of 6.91 nm, which exhibited the best photocatalytic performance. The polymerization rate under these conditions was 2.5 times higher than that of the control. The synergy among micropores, mesopores, and macropores enhanced photocatalytic efficiency by increasing surface area, promoting mass transfer, and improving charge carrier mobility. Spectroscopic and electrochemical analyses further revealed that the optimized pore structure significantly enhances charge carrier dynamics by facilitating charge separation and migration. This structural modulation effectively reduces charge recombination, thereby improving the photocatalytic efficiency in PET-RAFT polymerization. These findings provide valuable insights into the rational design of porous photocatalysts for advanced PET-RAFT systems.