N-doped carbon nanotubes encapsulated NiZnC nanoparticles catalyst for peroxymonosulfate activation: Heterojunction structure and N-doping enhance electron transfer capability.

In this paper, a type of N-doped carbon nanotube-coated NiZnC metal nanoparticle heterostructure catalyst (NZC-C-700) was prepared by two-step roasting method and applied to depredate bisphenol A (BPA) with peroxymonosulfate (PMS) activation. Characterizations and first principles calculation (DFT) reveal that the heterostructure formed by the graphite carbon layer and NiZnC metal nanoparticles, coupled with various N doping, can effectively modulate surface charge distribution, which could improve charge transfer capability between the catalyst and PMS. Meanwhile, the results of quenching experiments, electron paramagnetic resonance (EPR) and chronoamperometry proposed that the system is a typical singlet oxygen (O) -dominated non-radical pathway. Moreover, the NZC-C-700/PMS system has strong salt tolerance, high selectivity, and good practical application prospects. Finally, the results of LC-QTOF-MS/MS analysis proposed two possible paths of BPA degradation in the system. This work will provide a novel treatment process for organic wastewater purification.