Mechanical pressure-mediated Pd active sites formation in NaY zeolite catalysts for indirect oxidative carbonylation of methanol to dimethyl carbonate

Enhanced Fenton-like process via interfacial electron donating of pollutants over in situ Cobalt-doped graphitic carbon nitride

The heterogeneous Fenton process suffers from low efficiency because of the low electron transfer cycle rate of Fe³⁺/Fe²⁺, which often consumes enormous amounts of hydrogen peroxide (H₂O₂) or other energy. Herein, we report a novel Co-based Fenton-like catalyst (in-situ-Co-g-C₃N₄) synthesized via the surface complexation method, in which Co species were modified in situ into the framework of the graphitic carbon nitride (g-C₃N₄) substrate through C-O-Co chemical bonding. The catalyst exhibited higher Fenton-like catalytic activity than pure g-C₃N₄ in the degradation of various pollutants under neutral conditions, as evidenced by the approximately 150-fold higher Fenton-like reaction rate constant of in-situ-Co-g-C₃N₄ than that of g-C₃N₄. Density functional theory (DFT) calculations and a series of experimental and characterization analyses revealed the interfacial reaction mechanism between H₂O₂, pollutants and in-situ-Co-g-C₃N₄. During the Fenton-like reaction, the electron-poor C center on the aromatic ring of g-C₃N₄ could capture the electrons deprived from pollutants, and subsequently deliver them to around the electron-rich Co center to efficiently reduce H₂O₂ to hydroxyl radicals (^•OH), enabling H₂O₂ to be used efficiently for the degradation of pollutants. This study provides a strategy for improving Fenton-like degradation efficiency by effectively utilizing the energy of organic pollutants.