MXene terminating groups O, –F or –OH, –F or O, –OH, –F, or O, –OH, –Cl?

MXenes are a novel family of 2D materials with various surface terminal groups (O, –OH, –F, –Cl and –I). The priority of surface terminal groups is often determined by the fabrication method and post-synthesis heat-treatment. Various techniques e.g., 1H and 19F NMR, Raman, XANES, EXAFS, UPS, XPS/STEM, and TGA-MS may be applied to characterize the nature of the surface terminals.