Nanoconfinement-Regulated Peroxymonosulfate Activation via an Anomalously Efficient Mediated Electron-Transfer Pathway on Cobalt

In a nanoconfined space, the chemical/physical properties of molecules/ions can be fundamentally changed; the strategy of nanoconfinement thus offers rich opportunities for the development of an efficient catalytic process. Peroxymonosulfate (PMS) involved in advanced oxidation processes is a promising technology for efficient abatement of recalcitrant pollutants. Radical, singlet oxygen, and high-valent cobalt species are, hitherto, reckoned as the predominant reactive species for pollutant degradation in cobalt-catalyzed reaction systems. Herein, a distinctive mediated electron-transfer mechanism of cobalt was substantiated in a nanoconfined space. Moreover, an unusual pollutant-dependent PMS consumption behavior was revealed; the presence of pollutant unexpectedly attenuated the PMS consumption, which was contrary to the knowledge in the usual mediated electron-transfer mechanism of noble metals or carbon. By nanoconfinement regulation, the reaction system afforded an unprecedently efficient catalytic performance for pollutant degradation, for example, rapid elimination of bisphenol A and 2-chlorophenol with a high concentration of 100 ppm within 1 min and 40 s, respectively.