Nickel ferrite/MXene-coated carbon felt anodes for enhanced microbial fuel cell performance.

In recent years, the modification of electrode materials for enhancing the power generation of microbial fuel cells (MFCs) has attracted considerable attention. In this study, a conventional carbon felt (CF) electrode was modified by NiFe2O4 (NiFe2O4@CF), MXene (MXene@CF), and NiFe2O4-MXene (NiFe2O4-MXene@CF) using facile dip-and-dry and hydrothermal methods. In these modified CF electrodes, the electrochemical performance considerably improved, while the highest power density (1385 mW/m2), which was 5.6, 2.8, and 1.4 times higher than those of CF, NiFe2O4@CF, and MXene@CF anodes, respectively, was achieved using NiFe2O4-MXene@CF. Furthermore, electrochemical impedance spectroscopy and cyclic voltammetry results confirmed the superior bioelectrochemical activity of a NiFe2O4-MXene@CF anode in a MFC. The improved performance could be attributed to the low charge transfer resistance, high conductivity and number of catalytically active sites of the NiFe2O4-MXene@CF anode. Microbial community analysis demonstrated the relative abundance of electroactive bacteria on a NiFe2O4-MXene@CF anodic biofilm rather than CF, MXene@CF, and NiFe2O4@CF anodes. Therefore, these results suggest that combining the favorable properties of composite materials such as NiFe2O4-MXene@CF anodes can open up new directions for fabricating novel electrodes for renewable energy-related applications.