Bipyridinic Iron Single Atom in Metal–Organic Frameworks as Electronic Pump of H <sub>2</sub> O <sub>2</sub> for Continuous Water Decontamination
Limin Duan, Huihao Jiang, Borui Cai, Jiali Wang, Wenhao Wu, Daohui Lin, Kun Yang
Abstract
Abstract Although Fenton‐like reaction has emerged as a promising water decontamination technology, the electron scarcity and instability of H 2 O 2 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 H 2 O 2 , 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 H 2 O 2 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 H 2 O 2 , accompanying with pollutant polymerization on catalyst surface, greatly decreasing H 2 O 2 consumption. Meanwhile, organic pollutant greatly boosts · OH generation and inhibit the side reaction of H 2 O 2 losing electron in · BPY + ‐Fe directed Fenton‐like reaction, significantly increasing H 2 O 2 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 ( k N = 56–100 min −1 /M H2O2) for bisphenol A, p‐chlorophenol, phenol and tetracycline degradation with lower H 2 O 2 usage than reported Fenton‐like catalyst ( k N = 0.2–40 min −1 /M H2O2 , and achieving over 90% bisphenol A degradation efficiency for 10 h operation of continues‐flow reactor.