Degradation of norfloxacin with peroxymonosulfate activated by nanoconfinement Co3O4@CNT nanocomposite

In this work, the tube-filled nanocomposites Co3O4@CNTs were successfully prepared and applied for the first time in the permonosulfate (PMS) system to degrade norfloxacin (NX). Characterization results showed that Co3O4 nanoparticles served as independent templates and were randomly distributed onto the surface of the internal cavity of CNTs. After five cycles, the removal rate of NX decreased by only 4.5%, indicating its high catalytic activity and stability. This study also proposed a potential mechanism based on Co3O4@CNT/PMS system catalysis in which 1O2 was the main cause of NX degradation. DFT calculation results confirmed that the electronic activity of Co3O4 filled CNTs increased, and that the Co3O4 nanoparticles filled in the tube were the main catalytic sites of Co3O4@CNTs for NX degradation. This work provided the first insight into the effects of metal nanoparticles in the confined structure of CNTs on PMS activation.