Molybdenum sulfide Co-catalytic Fenton reaction for rapid and efficient inactivation of Escherichia coli

Abstract

As a typical advanced oxidation technology, the Fenton reaction has been employed for the disinfection, owing to the strong oxidizability of hydroxyl radicals (·OH). However, the conventional Fenton system always exhibits a low H₂O₂ decomposition efficiency, leading to a low production yield of ·OH, which makes the disinfection effect unsatisfactory. Herein, we develop a molybdenum sulfide (MoS₂) co-catalytic Fenton reaction for rapid and highly efficient inactivation of Escherichia coli K-12 (E. coli) and Staphylococcus aureus (S. aureus). As a co-catalyst in the Fe(II)/H₂O₂ Fenton system, MoS₂ can greatly facilitate the Fe(III)/Fe(II) cycle reaction by the exposed Mo⁴⁺ active sites, which significantly improves the H₂O₂ decomposition efficiency for the ·OH production. As a result, the MoS₂ co-catalytic Fenton system can reach up to 83.37% of inactivation rate of E. coli just in 1 min and 100% of inactivation rate within 30 min, which increased by 2.5 times than that of the conventional Fenton reaction. Furthermore, the ·OH as the primary reactive oxygen species (ROS) in MoS₂ co-catalytic Fenton reaction was measured and verified by electron paramagnetic resonance (EPR) and photoluminescence (PL). It is demonstrated an increased amount of ·OH generated from the decomposition of H₂O₂ in the presence of MoS₂, which is responsible for the rapid and efficient inactivation of E. coli and S. aureus. This study provides a new perspective for rapid and highly efficient inactivation of bacteria in environmental remediation.

Keywords: Bacterial inactivation; Co-catalytic; Fenton reaction; Molybdenum sulfide.