Microbial Electrosynthesis for Efficient CO2 Conversion Using MXene: Materials, Mechanisms, and Future Perspectives—A Short Review

Abstract

Microbial electrosynthesis (MES) has emerged as a promising bioelectrochemical technology for sustainable carbon dioxide (CO₂) utilization, enabling the direct conversion of CO₂ into value-added fuels and chemicals using electroactive microorganisms under mild operating conditions. MES provides a unique pathway for carbon recycling by coupling microbial metabolism with renewable electricity while preventing high complexity, temperature, and pressures associated with conventional thermochemical and electrochemical CO₂ conversion technologies. Despite its good potential, the practical implementation of MES remains restricted by slow microbial activity, electrode instability, low electron transfer efficiency, and challenges in long-term system performance. Among the various electrode materials explored for addressing these limitations, MXene-based electrodes have attracted increasing attention due to their high electrical conductivity, large surface area, and tunable surface chemistry. These properties position MXenes as strong candidates for enhancing electron transfer, promoting microbial attachment and improving overall MES performance. Nevertheless, the application of MXene-based electrodes in MES is still emerging, primarily constrained by their susceptibility to degradation in aqueous media that may affect electrode durability under prolonged operation. This review provides a comprehensive overview of MES systems, followed by critical examination of MXene-based electrodes for MES applications, with particular emphasis on studies reported in recent years. Key aspects discussed include the fundamentals of MES, recent progress in electrode materials, MXene synthesis, modifications, composite electrode designs, and their catalytic roles in enhancing CO₂ reduction performance. In addition, development in reactor configurations, performance metrics such as current density and product yield relevant to MXene-enhanced MES systems are evaluated. Furthermore, the remaining challenges related to long-term stability, scalability, microbial compatibility is identified, and potential strategies to overcome these limitations are proposed. Overall, this study provides comprehensive insights into the role of MXene-based electrodes in advancing MES technologies and outlines future research directions focused at facilitating their integration into efficient and sustainable CO₂ conversion systems.