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

Abstract

• Novel nitrogen-doped biochar encapsulated Fe/Mn nanoparticles was prepared. • Fe/Mn@NBC 800 showed superior adsorption performance and PMS-driven oxidative effect. • Both radical and non-radical pathways were involved in the degradation of BPA. • The mechanism of heterogeneous activation of PMS by the catalyst was elucidated. • Fe/Mn@NBC 800 manifested proposing potential in practical application. Nitrogen-doped biochar encapsulating Fe/Mn nanoparticles (Fe/Mn@NBC 800 ) was synthesized as a cost-effective catalyst for activating peroxymonosulfate (PMS) towards the degradation of bisphenol-A (BPA). Superior catalytic performance of Fe/Mn@NBC 800 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@NBC 800 , accelerating the electronic migration in the activation of PMS. Further investigation indicated radical pathways, especially SO 4 − and OH serve a predominant role in the oxidative decomposition of BPA. Also, O 2 − and non-radical ( 1 O 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@NBC 800 exhibited promising application prospects.