Fe3O4-supported N-doped carbon channels in wood carbon form etching and carbonization: Boosting performance for persulfate activating

Abstract

Fe-based carbon catalysts prove their great potential in activating persulfate for antibiotic wastewater treatment. Considering their limitation in reduced catalytic performance and large-scale application of powder catalysts, porous support catalysts provide an alternative solution. Herein, via Lewis acid (FeCl3) etching and carbonization, monolithic Fe3O4-supported N-doped wood-carbon catalysts were constructed. FeCl3 etching achieved the uniform dispersion of Fe into porous wood channels, but also enlarged the pore sizes with more structural defects. The hierarchical wood-carbon channels anchored with accessibly active Fe3O4 and induced graphitic N after carbonization allowed rapid electron transfer for peroxydisulfate (PDS) activation to eliminate norfloxacin (NOF). As anticipated, the prepared catalyst Fe-1–600 could make 99 % NOF degraded and 63 % TOC removed within 60 min in PDS system, and the corresponding first-order kinetic constant (0.0541 min−1) was 30 times that of C-600 (0.0018 min−1). Mechanism investigation revealed the role of Fe2+/Fe3+ conversion and the participation of generated SO4•-, •OH and O2•- in NOF oxidization. Further evaluations demonstrated the excellent catalytic activity of Fe-1–600/PDS system in wide pH ranges (2–10), as well as satisfactory antijamming capability towards various anions. This work proposed a facial way to fabricate monolithic Fe-based catalysts for persulfate excitation in antibiotic removal.