Multi-level porous layered biochar modified cobalt-iron composite as a reusable synergistic activator of peroxymonosulfate for enhanced tetracycline degradation

Background: Based on the advanced oxidation process of transition metal activated peroxymonosulfate (PMS), a heterogeneous catalyst with simple synthesis strategy and high efficiency was prepared. It was used to remove refractory organic pollutants. Methods: We designed a biochar modified cobalt-iron bimetallic composite catalyst (BC@CFC) via co-precipitation and calcination methods using biomass and cobalt-iron layered double hydroxide as precursors. Significant Findings: BC1@CF2C exhibited a unique multi-level porous layered structure, which reasonably reduced the agglomeration of cobalt-iron composite and increased the specific surface area. This allowed the catalyst to create more exposed active sites and favorably activate PMS, with a rapid and efficient degradation of tetracycline (TC) in 5 min (92.49%+/- 0.21%) and 30 min (96.63%+/- 1.68%). BC1@CF2C was magnetic and easy to recover, it maintained a superior TC removal rate (about 90%) after 5 cycles. This remarkable performance was benefited from the synergistic effect of cobalt-iron bimetal to enhance the activation effect of PMS, which led to the production of sulfate free radicals (SO4 center dot-) and hydroxyl free radicals (center dot OH) to further attack TC. BC@CFC possessed the advantages of being environment-friendly, high catalytic activity and sustainability, which could be of great value in environmental application. (C) 2022 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

In this study, a biochar modified cobalt-iron bimetallic composite catalyst with a unique multi-level porous layered structure was prepared. This catalyst demonstrated high efficiency in degrading refractory organic pollutants and possessed environmentally friendly and sustainable characteristics.