Efficient removal of organic pollutants by Metal–organic framework derived Co-N@C hollow multi-shell Nanoreactors: Size-Exclusion and confinement effect

The removal of organic pollutants in complex aqueous environments is often hindered by the presence of natural organic matter (NOM), such as humic acid (HA), which can interfere with pollutant degradation processes. Peroxymonosulfate (PMS) activation has emerged as a promising strategy for pollutant degradation; however, its efficiency is typically compromised by NOM interference. To address this challenge, this study develops a metal–organic framework (MOF)-derived Co-N@C hollow multi-shell nanoreactor (HoMS) that effectively isolates NOMs while targeting organic pollutants. The Co-N@C HoMS, synthesized via a “hierarchical temperature control, one-step pyrolysis” strategy, demonstrated superior catalytic performance in selectively degrading carbamazepine (CBZ) in the presence of HA. Over 99% of CBZ was removed within 10 min, even with HA present. Mechanistic studies revealed that PMS activation by Co-N@C HoMS for CBZ degradation involves both radical oxidation and electron transfer pathways. The unique size-exclusion effect of the Co-N@C HoMS selectively allows small molecules (CBZ) to pass through while blocking larger ones (HA), enabling rapid and selective pollutant degradation in complex environments. This work provides a novel solution for the efficient and selective removal of multi-component pollutants in complex environmental systems.