Unzipping carbon nanotubes to nanoribbons for revealing the mechanism of nonradical oxidation by carbocatalysis

•Carbocatalysts with tunable edge degrees were obtained via a nano-cutting strategy.•Boundaries are more active for the catalytic activation of peroxydisulfate (PDS).•Reaction kinetic rates are correlated to the defect speciation (ID/ID’).•A nonradical pathway is verified by in situ Raman and electrochemical measurements.•Deteriorated graphitization and conductivity undermine the edge-induced activity.