Nanoconfinement unlocks electron delocalization in carbon nanotubes-encapsulated CoMnO_x for efficient...

The efficient activation of peroxymonosulfate (PMS) has become a central focus in relevant research, highlighting the urgent need for constructing novel catalysts. To address this challenge, we engineered a nanoconfined catalyst by encapsulating CoMnO_x nanoparticles within carbon nanotubes (denoted as CMCNT-14). This catalyst possesses a high specific surface area, abundant actives, and reduced ion leaching. Fundamentally, the nanoconfinement architecture modulates the electronic structure, inducing electron delocalization at Co and Mn sites which optimizes charge transport efficiency and reduces the activation energy barrier. Consequently, the CMCNT-14/PMS system achieves superior tetracycline (TC) with degradation efficiency (92.9%, k = 11.4 × 10^-2 min^-1), which significantly outperform the unconfined counterpart. Mechanistic study revealed that the oxidation process is governed by a non-radical pathway, mainly involving singlet oxygen (¹O₂) and electron transfer. Moreover, nanoconfinement drastically suppresses the leaching of metal ion and eliminates the biotoxicity of the treated water, endowing the catalyst with excellent stability and environmental compatibility. This work elucidates the electronic-level benefits of nanoconfinement and provides a feasible strategy for designing advanced catalysts for sustainable water purification.