(771g) Insights on the Thermal Stability of V2CTx Mxene Under Different Environments

Two-dimensional (2D) transition metal carbides and nitrides (MXenes) have recently attracted much attention because of their electronic structure and properties that differ from their bulk counterparts. Since their discovery in 2011, MXenes have been extensively studied for various applications. The general formula for MXenes is M_n+1X_nT_x where M is an early transition metal, X is carbon and/or nitrogen, T indicates various surface terminations, n=1, 2 or 3, and x is the number of surface groups per unit formula. MXenes are produced by liquid exfoliation of MAX phases, the process results in selective removal of A layer elements (group 13 or 14 elements, i.e. Al) and formation of multilayered stacks of M-X 2D sheets.

The unique properties exhibited by MXenes, such as good electronic, mechanical, and optical properties as well as their hydrophilicity have remarkably driven the research and applications of MXenes for microelectronics sensors, water purification, energy storage, biosensors, hydrogen/oxygen evolution reactions etc. Amongst the reported MXenes, Ti₃C₂T_x has been studied the most to date.

In this presentation , we will report the thermal stability of V₂CT_x MXene under different atmospheres by combining in situ Raman spectroscopy with ex situ X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Scanning electron microscopy (SEM) in order to gain molecular-structural information from both the surface and bulk of these promising materials. The material was heated up to 600 °C under inert (N₂), oxidant (CO₂, air) and reductant (H₂) environments with similar contact time. By combining in situ and ex situ techniques, we demonstrated that the surface and bulk structure of V₂CT_x transform differently under different chemical environments as a function of time. We aim to foster both V₂CT_x and MXenes in general as potential thermo catalysts, beyond their already proved electro-catalytic applications.