Fe_1-xZn_xS ternary solid solution as an efficient Fenton-like catalyst for ultrafast degradation of phenol

Heterogeneous Fenton-like system has been proved to be an promising alternative to Fenton system due to its easy separation. However, it's a challenge to design heterogeneous Fenton-like catalysts with high activity and great durability. Here, ternary solid solution Fe_1-xZn_xS were prepared via hydrothermal synthesis as heterogeneous Fenton-like catalysts. The Fe_0.7Zn_0.3S sample exhibited state of the art activity for yielding OH by H₂O₂ decomposition, and the ultrafast degradation of phenol was achieved in 4 min at initial acidic condition under room temperature. The phenol degradation rate constant of Fe_0.7Zn_0.3S was 99 and 70 times of ZnS and FeS, respectively. Further, we show that the unique structural configuration of iron atoms, the formation of FeS₂-pyrite with (200) plane, are responsible for the excellent activity. The intermediate products were identified by LC-MS and a possible pathway was accordingly proposed to elucidate the mechanism of phenol degradation by OH. Overall, this work provides an idea for the rational design of the relevant heterogeneous Fenton-like catalysts.