Uniform N-coordinated single-atomic iron sites dispersed in porous carbon framework to activate PMS for efficient BPA degradation via high-valent iron-oxo species

Iron-mediated activation of peroxymonosulfate (PMS) has been widely investigated for recalcitrant pollutants. However, maximizing the dispersion degree of the active iron sites in the catalysts is still a great challenge and attracting tremendous attention. Herein, we demonstrated that well-dispersed single atomic Fe sites embedded into N-doped porous carbon (Fe-SA-N-C), which derived from chemically Fe-doped zeolitic imidazolate frameworks, could work as Fe-based catalyst for efficient catalytic oxidation of recalcitrant organics via PMS activation. As expected, Fe-SA-N-C exhibited remarkably higher degradation activity (8.1 times faster) to BPA (a model pollutant) than that of Fe based nanoparticles-loaded N-doped carbon (Fe-NP-N-C). The sufficient Fe-N-x sites with single Fe atom as the building units were proposed to be the main active sites for PMS activation. Based on that, unlike the traditional sulfate radical-based advanced oxidation processes, BPA degradation was achieved via high-valent iron-oxo species. More particularly, it could be used over a wide range of pH 3.0-7.5 with almost no loss of degradation efficiency. This study will provide insights into the design of heterogeneous Fenton-like catalysts.