Anchoring CuFe2O4 nanoparticles into N-doped carbon nanosheets for peroxymonosulfate activation: Built-in electric field dominated radical and non-radical process

Radical and non-radical dominated PMS activation has been widely researched, but the driving force of this process is not well understood. Herein, CuFe2O4 nanoparticles anchored on nitrogen-doped carbon nanosheets (CFONC-2) was prepared for investigation. Experimental results and DFT calculations indicate that a built-in electric field (BIEF) is formed between CuFe2O4 and N-doped carbon nanosheets, which is proposed as the driving force to adjust the electron transfer for triggering radical and non-radical pathway. Specifically, Cu+/Cu2+ and Fe2+/Fe3+ redox cycles are regarded to be the dominant catalytic sites for radical generation (SO4•–, HO• and •O2–). Whereas graphitic N, sp2-hybridized structure, as well as C = O functional group are main active sites for non-radical production (1O2 and direct electron transfer process). Under the radical and non-radical processes dominated by BIEF, the CFONC-2/PMS system exhibits excellent removal performance of levofloxacin (LVFX), where 84.87% of LVFX is removed in 90 min. This work offers a feasible strategy for designing metallic oxides-carbon catalyst with strong electric field effect to satisfy the charge transfer in PMS catalytic reaction.