Synthesis of Two-Dimensional Nb1.33C (MXene) with Randomly Distributed Vacancies by Etching of the Quaternary Solid Solution (Nb2/3Sc1/3)2AIC MAX Phase

Introducing point defects in two-dimensional (2D) materials can alter or enhance their properties. Here, we demonstrate how etching a laminated (Nb2/3Sc1/3)(2)AlC MAX phase (solid solution) of both the Sc and Al atoms results in a 2D Nb1.33C material (MXene) with a large number of vacancies and vacancy clusters. This method is applicable to any quaternary, or higher, MAX phase, wherein one of the transition metals is more reactive than the other and could be of vital importance in applications such as catalysis and energy storage. We also report, for the first time, on the existence of solid solution (Nb2/3Sc1/3)(3)AlC2 and (Nb(2/3)Sc(1/)3)(4)AlC3 phases.