Photogenerated and cocatalytic system cooperate to accelerate Fe3+/Fe2+ cycle in CNFe/FeS2/MoS2 composite with Z-scheme heterojunction constructed by interfacial chemical bond for advanced oxidation processes

Currently, the utilization of Fenton or Fenton-like reactions is prevalent in various domains such as environmental control, biology, and life science. In this study, we drew inspiration from the MoS2 cocatalytic heterogeneous Fenton system and devised CNFe/FeS2/MoS2 heterojunction. This heterojunction is connected through atomic-level Fe-S-Mo and Mo-N interfacial chemical bonds, serving as a catalyst for synergistic photocatalytic effects in conjunction with Fenton reactions. The suitable Mo/Fe molar ratio of 1.5 gives the CNFe/FeS2/MoS2 catalyst higher conductivity and higher carrier separation efficiency. The utilization of dual reduction approaches involving photo-generated electrons and Mo4+ effectively facilitates the stable circulation of Fe3+/Fe2+ with high efficiency in an acidic microenvironment, which is facilitated by the S-SO4 2- edge of MoS2. Moreover, the CNFe/FeS2/MoS2 heterojunction exhibits enhanced production of center dot O2 and H2O2. This effect not only reduces the quantity of hydrogen peroxide generated but also contributes to cost reduction. This work not only experimentally verifies the coupling effect of heterojunction and cocatalytic heterogeneous Fenton system but also provides a new idea for the design of efficient advanced oxidation processes (AOPs).