Built-in electric field-enhanced electron super-exchange interactions for non-radical activation in ultra-thin FeOCl/g-C3N4 nanosheets

Strong electronic interactions between heterogeneous composite catalysts play an essential part in the enhancement of their catalytic capacity. Herein, utilizing the difference in the work functions of g-C3N4 and FeOCl to modulate the built-in electric field (BIEF), ultra-thin FeOCl/g-C3N4 composite nanosheets (FeOCl-CN) were synthesized for rapid peroxymonosulfate (PMS) non-radical activation. The resulting 1O2 could remove 96.2% of bisphenol AF (BPAF) within 30 min with its excellent reusability and environmental suitability. Due to the different work functions, some electrons delocalization from g-C3N4 to FeOCl led to the formation of the BIEF by DFT calculations. The BIEF can drive charge transfer to induce the non-radical pathway by PMS and facilitate the Fe3+- O- Fe2+ electronic super-exchange interactions to accelerate the Fe3+/Fe2+ redox cycle for better degradation of BPAF. This work deepened the understanding of strong electronic interactions in heterogeneous catalysts based on PMS-AOPs.