Bipyridinic Iron Single Atom in Metal–Organic Frameworks as Electronic Pump of H2O2 for Continuous Water Decontamination

Abstract

Although Fenton‐like reaction has emerged as a promising water decontamination technology, the electron scarcity and instability of H2O2 for hydroxyl radicals (·OH) generation still remain a fundamental challenge. Considering organic pollutants as an electron reservoir, this work cleverly designs an electronic pump of H2O2, i.e., bipyridinic iron single atom (BPY‐Fe), into metal–organic frameworks, by using an anchored ligand. In situ experiment and theoretical calculation reveal that the adsorbed H2O2 on Fe sites can induces intramolecular electron transfer of BPY‐Fe to form BPY organic radical (·BPY+), which ·BPY+‐Fe sites can capture single electron of organic pollutants and further unidirectionally transport it to H2O2, accompanying with pollutant polymerization on catalyst surface, greatly decreasing H2O2 consumption. Meanwhile, organic pollutant greatly boosts ·OH generation and inhibit the side reaction of H2O2 losing electron in ·BPY+‐Fe directed Fenton‐like reaction, significantly increasing H2O2 utilization efficiency. Benefiting from BPY‐Fe electronic pump, the constructed Fenton‐like catalyst exhibits both superior activity and long‐term stability, delivering higher reaction rate constant (kN = 56–100 min−1/MH2O2) for bisphenol A, p‐chlorophenol, phenol and tetracycline degradation with lower H2O2 usage than reported Fenton‐like catalyst (kN = 0.2–40 min−1/MH2O2, and achieving over 90% bisphenol A degradation efficiency for 10 h operation of continues‐flow reactor.