Peroxymonosulfate activation by cobalt particles embedded into biochar for levofloxacin degradation: Efficiency, stability, and mechanism

Embedding metal particles into carbonaceous materials has promising prospects in antibiotic removal because of its good peroxymonosulfate (PMS) activation efficiency and low metal leaching risk. However, previous studies focused on metal particles embedding nanotubes, which is limited by high cost and complex preparation processes. Hence, in this study, low-cost and easily obtained biochar (BC) was chosen to prepare Co nanoparticles (Co NPs) embedded into carbonaceous materials through a one-step facile pyrolysis method. The optimized [email protected] exhibited excellent PMS activation efficiency toward levofloxacin (LVF) degradation. Compared to the structure of conventional Co particles loaded on the surface of BC (Co-BC), this special structure of Co NPs embedded into BC exhibited more stability in cycle experiments and negligible Co ion leaching. Based on the quenching experiment, electron paramagnetic resonance (EPR), in situ Raman testing, electrochemical analysis, and density functional theory (DFT) calculations, it was found that the 1O2 and electron transfer mechanisms played a dominant role in LVF degradation in the [email protected]/PMS system. In addition, [email protected] displayed excellent anti-interference ability, easy recovery performance and universal applicability. This work supplies a new means for the rational modification of BC materials for high-efficiency PMS activation performance with little metal ion leaching risk in antibiotic removal, which is proven by an in-depth exploration of the reaction mechanism.