Outstanding catalytic performance of metal-free peroxymonosulfate activator: Important role of chrysotile

A metal-free peroxymonosulfate catalyst based on chrysotile and graphite carbon nitride (g-C 3 N 4 ) was synthesized for the first time. The abundant hydroxyl groups of chrysotile can react with amine groups of urea-derived intermediates and accelerate formation of double nitrogen defects (N-vacancy and cyano group) in g-C 3 N 4 , which can drastically improve the activation efficiency of PMS. The introdution of chrysotile can greatly increase the reaction time of hydroxyl and amine groups, and promote the generation of double nitrogen defects. This catalyst displayed superior catalytic performance for rhodamine B (RhB) degradation than bare chrysotile and g-C 3 N 4 . Moverover, this catalyst also has good cycle performance, structural stability and universal applicability, which provides an idea for the comprehensive utilization of asbestos tailings and environmental remediation.