A comprehensive review of MXene-based materials for microbial fuel cell applications

Microbial fuel cells (MFCs) are innovative bioelectrochemical systems that can concurrently treat wastewater and generate bioelectricity; however, their efficacy is strongly influenced by electrode characteristics and electron-transport efficiency. This analysis rigorously evaluates the latest developments in MXene-derived materials for MFC anodes and cathodes, emphasising their physicochemical characteristics, electrode enhancement techniques, electrochemical processes, and documented performance. The elevated electrical conductivity, water affinity, adjustable surface chemistry, and available surface area of MXenes can facilitate microbial attachment, extracellular electron transfer, charge transport, and oxygen-reduction processes. Recent MXene composites integrating carbon materials, conductive polymers, metal oxides, nanoparticles, and porous architectures are evaluated for power generation, current output, wastewater remediation, and durability. Despite encouraging advances in laboratory settings, direct comparisons are challenging because MXene composition and loading, electrode arrangement, substrate, reactor design, and performance reports vary. Major obstacles include MXene oxidation, nanosheet reaggregation, coating deterioration, leaching, microbiological interactions, environmental impacts of synthesis, and scalability issues. Future investigations should emphasise consistent assessment, long-term operational studies in real wastewater, and comprehensive techno-economic and life-cycle evaluations. In general, MXenes show potential; however, their practical application has not been adequately confirmed under authentic continuous-flow and pilot-scale operational circumstances.