In photoinduced electron/energy transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization, developing photocatalysts with broad-spectrum light absorption and high catalytic efficiency is crucial. Carbon nitride (C3N4) shows great promise in PET-RAFT polymerization due to its appropriate band gap and favorable photochemical properties. In this work, the electron-donating moiety Aphen was successfully incorporated into the C3N4 framework via a low-temperature solid-phase synthesis, yielding a donor (D)-acceptor(A) photocatalyst (Aphen@C3N4) with enhanced intramolecular charge transfer characteristics. This structural design effectively extends the optical absorption range and suppresses the recombination of photogenerated charge carriers of C3N4, leading to significantly improved photocatalytic performance. Experimental results show that Aphen@C3N4 exhibits superior activity in PET-RAFT polymerization compared to pristine C3N4, enabling high monomer conversion and excellent control over molecular weight dispersity across various solvents. Furthermore, the catalyst demonstrates broad monomer compatibility, accommodating both conjugated and non-conjugated monomers, and facilitates the precise synthesis of homopolymers and block copolymers with narrow molecular weight distributions and high end-group fidelity. The study provides a novel and unique paradigm for tailoring C3N4 catalysts through small-molecule modification to achieve efficient controlled photopolymerization.
Bei et al. (Wed,) studied this question.