Microbial photo electrosynthesis for efficient CO2 conversion using MXenes: Materials, mechanisms, and applications

The current review article explores the emerging role of MXene materials in microbial electrosynthesis (MES) for carbon dioxide (CO2) reduction, offering an insight on sustainable bioproduct synthesis. MXenes, twodimensional materials with distinctive properties, have attracted significant attention for their excellent electrical conductivity, surface functionality, and biocompatibility. This article presents recent advancements in MXene-based electrodes for CO2-reduction in MES systems, elucidating their potential to enhance CO2 conversion efficiency. MXenes have been harnessed as efficient cathodes in MES setups, fostering the reduction of CO2 through microbial activities. Functionalizing MXene cathodes with carbon nanotubes or other nanomaterials has demonstrated improved yields of useful products. However, challenges persist, including scalable MXene synthesis, the ecological impact of toxic etching processes, and stability concerns in corrosive environment. Addressing these hurdles require sustainable and efficient synthesis methods, as well as a comprehensive understanding of the CO2-reduction mechanisms on MXene surfaces. Moreover, strategies to mitigate electrode fouling, bacterial damage, and side reactions are essential to realize the full potential of MXene-based MES. Promisingly, innovative approaches like the incorporation of cytoprotective layers using metal-organic frameworks have demonstrated the potential to counteract bacterial damage caused by reactive radical species formed during photocatalysis. A comprehensive understanding of microbe-MXene interactions is crucial to achieve high product yield. Additionally, fundamental insights on scalable synthesis techniques, improved CO2 adsorption, and optimized reaction conditions will be pivotal in advancing the application of MXenes in the MES systems. The integration of MXene-enabled MES process holds the promise of sustainable CO2-reduction and the synthesis of valuable bioproducts.