Affordable combustion synthesis of V2AlC precursor for V2CTx MXene

Two-dimensional (2D) transition metal carbides and nitrides (MXenes) possess a unique combination of properties, such as metallic conductivity combined with hydrophilicity and surface redox activity, that are important for energy storage, printed electronics, biomedical, catalytic and other applications. However, the use of many MXene chemistries beyond titanium carbides is limited by the cost of MAX phase precursors, which are usually produced from pure elements, involving expensive transition metals. Herein, we demonstrate a low-cost rapid aluminothermic combustion synthesis of MAX phases from an inexpensive oxide precursor, producing V2AlC in seconds, with low energy input. A reactor for self-propagating high-temperature synthesis (SHS) was designed and manufactured for this study. The V2CTx MXene produced from the SHS MAX is similar to MXene from conventional pressureless sintered MAX in terms of oxidation resistance, environmental stability, conductivity, and electrochemical performance, but has a larger flake size. This work demonstrates an alternative, low-cost and scalable approach to the synthesis of MAX phases and, subsequently, MXenes without sacrificing their properties.