Nitrogen-doped biochar encapsulated Fe/Mn nanoparticles as cost-effective catalysts for heterogeneous activation of peroxymonosulfate towards the degradation of bisphenol-A: Mechanism insight and performance assessment

Nitrogen-doped biochar encapsulating Fe/Mn nanoparticles (Fe/Mn@NBC800) was synthesized as a cost-effective catalyst for activating peroxymonosulfate (PMS) towards the degradation of bisphenol-A (BPA). Superior catalytic performance of Fe/Mn@NBC800 was observed as BPA was completely degraded within 20 min and with a reaction rate 75.88-fold higher than that of pristine biochar. This observation ascribed to redox cycles between Fe and Mn with multivalent states and nitrogen functionalization in Fe/Mn@NBC800, accelerating the electronic migration in the activation of PMS. Further investigation indicated radical pathways, especially SO4 center dot- and (OH)-O-center dot serve a predominant role in the oxidative decomposition of BPA. Also, O-2(center dot-) and non-radical (O-1(2)) assumed an indispensable role in this process. Environmental factors had little effect on the synergistic process of radical and non-radical. The potential BPA degradation pathway was inferred by Density Functional Theory (DFT) calculation and intermediates analysis. In terms of excellent separability, reusability, stability, and universality, Fe/Mn@NBC800 exhibited promising application prospects.

Automated summary

The newly synthesized Fe/Mn@NBC800 catalyst exhibited superior catalytic performance in activating PMS for the degradation of BPA, attributed to the redox cycles between Fe and Mn and nitrogen functionalization. Radical and non-radical pathways played key roles in the oxidative decomposition of BPA, with environmental factors having minimal impact on this synergistic process.