A universal method for preparing biomass derived topologically defective carbons with superior catalytic performance in cationic radical polymerization

This study aims to develop a universal preparation method for biomass-derived topologically defective carbons and reveal the catalytic mechanism of such carbons for cationic radical polymerization. Firstly, bamboo fiber-derived topologically defective carbon (BFTC) is prepared by an ammonia-assisted heat treatment method. BFTC can significantly promote the chemical oxidative polymerization of 3-aminophenylboronic acid (a typical cationic radical polymerization process) and obtain high molecular weight products, which is mainly attributed to the rich topological defect structure of BFTC. Secondly, the ammonia-assisted heat treatment method is applied to two other biomasses, and the derived carbons have similar microstructure and chemical composition to BFTC, indicating the universality of this method at the material preparation level; meanwhile, these derived carbons also exhibit excellent catalytic properties when they promote 3-aminophenylboronic acid (ABA) polymerization, which further confirms the universality of this method from the perspective of material properties. Finally, research on the catalytic mechanism shows that there is an interaction based on partial electron transfer between the topological defects of the carbon catalyst and ABA or ABA-derived radical. This effect promotes the rapid derivatization of ABA into cationic radical, and also improves the stability of the radical, thereby achieving efficient polymerization of ABA around the topological defect active center. Therefore, this study confirms the universality of the ammonia-assisted heat treatment method to prepare biomass-derived topologically defective carbon, and such defective carbons are likely to serve as catalysts for cationic radical polymerization.