Advances in MXene surface functionalization modification strategies for CO 2 reduction.

MXenes, 2D transition metal carbides and nitrides, show great potential in electrocatalytic CO 2 reduction reaction (ECO 2 RR) applications owing to their tunable structure, abundant surface functional groups, large specific surface area and remarkable conductivity. However, the ECO 2 RR has a complex pathway involving various reaction intermediates. The reaction process yields various products alongside a competitive electrolytic water-splitting reaction. These factors limit the application of MXenes in ECO 2 RRs. Therefore, this review begins by examining the functionalized modification of MXenes to enhance their catalytic activity and stability via the regulation of interactions between carriers and the catalytic centre. The review firstly covers the synthesis methods and characterisation techniques for functionalized MXenes reported in recent years. Secondly, it presents the methods applied for the functionalized modification of carriers through surface loading of single atoms, clusters, and nanoparticles and construction of composites. These methods regulate the stability, active sites, and metal-carrier electronic interactions. Finally, the article discusses the challenges, opportunities, pressing issues, and future prospects related to MXene-based electrocatalysts.