Effect of functionalization on the electronic and atomic properties of layered MXenes

MXenes (M $=$ Transition Metal, X $=$ C or N) are a promising family of materials that have been recently manufactured from MAX phases. MXenes have already been shown as promising candidates for use in lithium ion batteries, supercapacitors, and fuel cells (1). MXenes consist of M\textunderscore (x)X\textunderscore (x-1), two-dimensional sheets weakly bound by van der Waals forces. However, due to the selective removal of the A ion to manufacture MXenes, they are highly reactive, with a wide variety of possible functional groups. Previous studies have shown that the electronic properties of MXene single sheets are highly dependent on their functionalization, but so far there are few studies on the effect of functionalization of the bulk phase of MXene, which consists of many layers of MXenes bound together. In this talk, we will illustrate the effect of functionalization of bulk MXenes by H, H$_{\mathrm{2}}$, OH, and O for Mo$_{\mathrm{2}}$C and Ti$_{\mathrm{2}}$C. We will also show the effect of applied potential on the functionalization of Mo$_{\mathrm{2}}$C and Ti$_{\mathrm{2}}$C. Finally, we will compare our results with experimental measurements. (1) M. Naguib, V.D. Mochalin, M.W. Barsoum and Y. Gogotsi, \textit{Adv. Mater.} \textbf{26}, 992 (2014).