Electrospun Co3O4/CeO2 hollow nanotubes for photocatalytic degradation of PET plastics with peroxymonosulfate activation: Performance and DFT insight.

Polyethylene terephthalate (PET) plastics cause significant environmental harm. Traditional treatment methods, such as landfilling and incineration, can cause secondary pollution. Here, an efficient synergistic photocatalytic system is presented, based on Co3O4/CeO2 hollow nanotubes prepared by electrospinning, to activate peroxymonosulfate (PMS) and promote the degradation of PET plastics. The results show that the as-prepared Co3O4/CeO2 composite catalyst exhibits the best performance under illumination; the weight loss rate of PET can reach ∼82.7 ± 4.5% in the presence of a 3 mM PMS solution (pH 7). The effects of parameters (e.g., PMS dose and coexisting anions) on PET degradation were systematically investigated. Electron paramagnetic resonance (EPR) and free radical quenching experiments confirm that the •OH, 1O2, and SO4•- active species contribute the most to the degradation of PET plastics. Density Functional Theory analysis shows that Co-d-pDOS and Ce-f-pDOS modulations in Co3O4/CeO2 synergistically enhance the PET photocatalytic decomposition efficiency. Finally, we discuss the mechanism by which the catalyst/light/PMS system degrades PET in water.