Fe-nanocluster embedded biomass-derived carbon for efficient photo-Fenton-like activity in water purification

Single-atom catalysts (SACs) as photo-Fenton-like catalysts have attracted widespread attention in water purification. However, the development of SACs with renewability, cleanliness, high mass loading, and raw material abundance is a formidable challenge to achieve efficient pollutant removal. In this study, we fabricated high-performance Fe-nanocluster embedded biomass-derived carbon (Fe/Bio-C) from Ficus altissima wastes for quinolone antibiotics degradation. The high-angle annular dark-field scanning transmission electron microscopy with aberration correction (AC-HAADF-STEM) and X-ray absorption fine structure spectroscopy (XAFS) revealed that the Fe/Bio-C exhibited a porous structure with abundant Fe-N4 active sites. The Fe/Bio-C catalysts achieved an exceptional efficiency of 98.6 % for the removal of the representative quinolone antibiotic, namely lomefloxacin (LOM), within 30 min. Furthermore, an in-depth exploration was conducted to assess the influence of reaction parameters on degradation performance, kinetics, toxicity, and mechanism. The free radical quenching experiments and electron paramagnetic resonance (EPR) spectra demonstrated the existence of ·O2−, 1O2, ·OH, SO4·− in the reaction system and the ·O2− radicals played a relatively important role in the degradation progress. This work broaden the avenue for constructing metal-nanocluster photocatalysts with the high reactivity, low metal leaching, and universality to various pollutants.