  Two-dimensional (2D) transition metal carbides and nitrides (MXenes) are a
large family of materials actively studied for various applications, especially
in the field of energy storage. To date, MXenes are commonly synthesized by
etching the layered ternary compounds, MAX phases. Here we demonstrate a direct
synthetic route for scalable and atom-economic synthesis of MXenes, including
phases that have not been synthesized from MAX phases, by the reactions of
metals and metal halides with graphite, methane or nitrogen. These directly
synthesized MXenes showed excellent energy storage capacity for Li-ion
intercalation. The direct synthesis enables chemical vapor deposition (CVD)
growth of MXene carpets and complex spherulite-like morphologies. The latter
form in a process resembling the evolution of cellular membranes during
endocytosis.
