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 Co@RBC800 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 O-1(2) and electron transfer mechanisms played a dominant role in LVF degradation in the Co@RBC800/PMS system. In addition, Co@RBC800 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.

Automated summary

Embedding Co nanoparticles into carbonaceous materials has shown promise in antibiotic removal due to its high stability, low metal leaching risk, and low cost.