Exfoliation of Ti2C and Ti3C2 Mxenes from bulk trigonal phases of titanium carbide: A theoretical prediction. (September 2019) - Mondal, Krishnakanta
Abstract: MXenes, a novel class of two dimensional materials with several interesting properties, are prepared from their MAX phases by etching out the A element using strong chemical reagents. This results in passivation of the surfaces of MXene with different functional groups like O, –OH, –F, etc., which in many cases tend to degrade their properties. In this work, using first principle density functional theory based calculations, we propose a novel method that might open up possibility of synthesizing pristine Ti2 C and Ti3 C2 from the bulk titanium carbides with corresponding stoichiometry. Based on the values of cleavage energy obtained from our calculations, we envisage that pristine Ti2 C and Ti3 C2 MXenes can be prepared, using mechanical or sonication-assisted liquid-phase exfoliation techniques, from their bulk phases. Highlights: Weak interlayer interactions in bulk trigonal Ti2 C and Ti3 C2 . Exfoliation energies of Ti2 C and Ti3 C2 from bulk carbides are 1.81 and 1.51 J/m 2 . These are larger than that observed for typical van der Waals materials. These exfoliation energies are comparable to other quasi 2D systems, eg. GeP3 (1.14 J/m 2 ).