Localization of anionic electrons on Ti₂N and Ti₃N₂ MXene electrides

The graphene-like structured inorganic compounds with a stoichiometric formula of M_n+1X_n, where M is an early transition metal such as titanium (Ti), vanadium (V), chromium (Cr), zirconium (Zr), etc., and X being carbon (C), nitrogen (N) or CN, known as MXenes, possess many excellent properties needed for the current technological advancement such as high electrical and thermal conductivities, ultra capacity capacitance, interlayer space tunability, larger surface-to-volume ratio, hydro-compatibility, and so on. Performing the density functional theory (DFT)--based ab initio quantum mechanical calculations using the Vienna ab initio simulation package (VASP) software program, we calculated electronic structures and analyzed electronic and magnetic properties of Ti₂N and Ti₃N₂ MXenes. We discovered that Ti₂N and Ti₃N₂ MXenes have several non-nuclear interstitial anionic electrons (IAEs) trapped within the positively charged lattice framework, making them candidates for an under-explored class of electride materials. The comparatively low work function of these MXene-electrodes brings a promising application in electron emitters, electro-catalytic oxidations, and anodes in batteries. Reference: Adhikari, C.M.; Thapa, D. et al. (2024), arXiv:2408.00897.

The Department of Energy BES-RENEW award number DE-SC0024611 has supported this research work.