In situ HO production from self-sufficient heterogeneous Fenton reaction over Fe/MoS for potential environmental remediation applications.

Fenton reaction technology has worked well in water and wastewater treatment; however it is often limited by such problems as continuous external supply of HO, slow Fe/Fe cycle rate, high energy requirements, and maintenance of low pH during operation. Herein, a novel self-sufficient heterogeneous Fenton system based on Fe/MoS was designed, fabricated, and optimized to effectively address these problems. The combined presence of Fe and sulfur vacancies sites in MoS played a pivotal role in the generation of HOvia two-step single-electron reduction process without any energy consumption. The existence of dual active sites resulted in a considerable increase in the HO yield (up to 0.6 mM/g/h) in a pH-neutral aqueous solution. Furthermore, the Fe/Fe cycle rate was accelerated by Mo/Mo/Mo sites. The factors collectively contributed to the impressive performance of the reaction in degrading complex pollutants (e.g., polyethylene, a model plastic matter) under pH-neutral conditions. In addition to its outstanding catalytic performance, Fe/MoS exhibited superior reusability and stability. Notably, the catalyst reactivity was well sustained in the presence of common competitive factors such as inorganic anions and dissolved organic pollutants, and for other polymer types. This study demonstrates that Fe/MoS with impressive self-sufficient Fenton reaction capacity has greater potentials for water and wastewater treatment.