Visible-Light-Driven MADIX Polymerisation via a Reusable, Low-Cost, and Non-Toxic Bismuth Oxide Photocatalyst

The continuous amalgamation of photocatalysis into existing reversible deactivation radical polymerisation (RDRP) processes has initiated a rapidly propagating area of polymer research in recent years. We introduce bismuth oxide (Bi₂ O₃ ) as a heterogeneous photocatalyst for polymerisations, operating at room temperature with visible light. We demonstrate formidable control over degenerative chain-transfer polymerisations, such as macromolecular design by interchange of xanthate (MADIX) and reversible addition-fragmentation chain-transfer (RAFT) polymerisation. We achieved narrow molecular weight distributions and attribute the excellent temporal control of a photo-induced electron transfer (PET) process. This methodology was employed to synthesise diblock copolymers combining differently activated monomers. The Bi₂ O₃ catalyst system has the additional benefits of low toxicity, reusability, low-cost, and ease of removal from the reaction mixture.