MoS₂ nanosheets embedded in α-FeOOH as an efficient cathode for enhanced MFC-electro-Fenton performance in wastewater...

Microbial fuel cell-electro-Fenton system (MEF) has attracted attention due to refractory organic pollutants removal, where H₂O₂ is in-situ produced without external energy supply. Enhancement of H₂O₂ production and the activation of H₂O₂ to ·OH are the keys to improve degradation performance. Development of bifunctional catalytic cathode is a viable strategy. Herein, the α-FeOOH/MoS₂ nanocomposites was fabricated by a novel facile hydrothermal method based on molybdenite-exfoliated MoS₂ nanosheets suspension, which was used as modified cathode in a MEF system. The obtained α-FeOOH/1 wt%MoS₂ cathode exhibited highest power density of 292.38 mW/m², which was about 3.7 and 1.7 times higher than that of graphite plate and α-FeOOH, respectively. Doping of MoS₂ nanosheets significantly enhanced electrocatalytic activity of the cathode and promoted in-situ H₂O₂ generation. Meanwhile, the exposed reductive Mo⁴⁺ on the surface of MoS₂ could greatly facilitate the conversion cycle of Fe(III)/Fe(II), leading to the efficient activation of H₂O₂ into ·OH. The MEF with α-FeOOH/1 wt%MoS₂ cathode exhibited excellent degradation and mineralization performance for MB, rhodamine B and tetracycline hydrochloride at optimized reaction condition. Furthermore, the MEF can simultaneously achieve MB oxidation and Cr(VI) reduction, and the corresponding removal ratio can reach up to 91.45% and 100%, respectively. Based on simple preparation method as well as recyclability and excellent catalytic property, the α-FeOOH/MoS₂ composite catalyst is considered as a promising MEF cathode for efficient wastewater treatment.