Target prepared Nitrogen-Doped lignin biochar anchored Co-Mn oxides for directed singlet oxygen generation in fenton-like Reactions: Performance and mechanism.

Converting lignin into biochar-based Fenton-like catalysts represents a promising strategy for the upgrading of lignin. Herein, Co-Mn layered bimetallic oxides (CML) was anchored onto nitrogen-doped lignin biochar (NLBC) to achieve targeted enhancement of singlet oxygen (1O2) generation in peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs). The NLBC-anchored CML (CMLN)/PMS system achieved nearly completely (>99%) degradation of antibiotics within 20 min with the kobs of 0.28 min-1. It maintained excellent catalytic performance in real-water environments and across a wide pH range, remaining over 85% catalytical activity after 4 cycles. Experiments and theoretical calculations demonstrated that the NLBC anchoring strategy induces localized charge redistribution, enhancing the electron density at Co sites and promoting electron transfer. Moreover, NLBC favored the preferential coordination PMS with electron-rich Co sites, thereby achieving targeted enhancement of 1O2 generation. Overall, this work offers a promising strategy for value-added conversion of lignin resources into efficient Fenton-like catalysts for wastewater treatment.