Edge-Hosted Graphitic\nNitrogen Sites Carbocatalysts\nMediated Electron Transfer Process for Powerful Fenton-Like Reactions

The nonradical electron transfer process (ETP) without\nthe preliminary\ndecomposition of peroxymonosulfate (PMS) contributes to a green and\nsustainable water treatment. Moreover, the target regulation of ETP\nin PMS-based Fenton-like reactions has important practical significance,\nand the corresponding mechanism still needs to be further clarified.\nHere, by introducing edge-hosted graphitic nitrogen sites into carbocatalysts\n(E-gNC), we demonstrate the first achievement in subjectively regulating\nETP via microenvironment engineering of active sites. The E-gNC exerts\na highly efficient performance for phenol degradation via an ETP regime,\nwhile its counterpart with abundant pyridinic nitrogen sites (pNC)\nproduces multiple reactive oxygen species (ROSs). The turnover frequency\n(TOF) of E-gNC (5.38) is about 20 times that of pNC (0.27), and its\ndegradation rate is also superior to those of most reported carbocatalysts.\nIn situ spectra and theoretical simulations reveal that the electricity-deficient\nedge-hosted graphitic N sites and their neighbor C sites can simultaneously\nadsorb the O<sub>β</sub> and S atoms of PMS, respectively, facilitating\nthe formation of metastable E-gNC-PMS<sup>*</sup> active complex rather\nthan the decomposition of PMS. Compared with the traditional methods\nof premixed PMS and pollution, the E-gNC/PMS system can save about\n45% of PMS, demonstrating great potential for practical application.\nThis work reveals the intrinsic mechanism by which the microenvironment\nof N sites influences PMS-based Fenton-like reactions at the atomic\nlevel, paving avenues for new vitality of this ancient material in\nwater treatment.