Design Strategies of 2D MXene-Based Materials for CO₂ Electrolysis and Li-CO₂ Batteries

With increasing atmospheric CO₂ concentrations and their associated environmental challenges, the electrochemical carbon fixation process is of interest as a green and sustainable strategy to obtain future carbon-neutral energy cycles. Nonetheless, most existing catalysts still fail to meet the demands of the efficient CO₂ conversion process because of limited activity, poor selectivity, and high cost. Two-dimensional (2D) MXene-based materials have currently gained growing attention as potential candidates for the electrocatalytic CO₂ conversion process by their high conductivity, controllable surface chemistry, and intrinsic hydrophilicity. We herein critically summarize current progress in optimizing adsorption energies of key intermediates, product selectivity, and overall electrocatalytic efficiency of MXene-based electrocatalysts through various modification strategies; namely, defect and doping engineering, surface and interfacial construction, alloying and single-atom catalyst design, and synergistic coupling influences. The working mechanisms and structure-performance relationships of MXene-derived catalysts for CO₂ electrolysis and Li-CO₂ batteries are elucidated. Finally, current challenges and prospects of MXene-derived materials are discussed to provide valuable insights for designing advanced CO₂ conversion electrocatalysts.