Two-dimensional materials by large-scale computations and chemical exfoliation of layered solids.

Abstract

MXenes are a family of two-dimensional (2D) materials typically formed by etching the A element from a parent MAX phase. Computational screening for other 3D precursors suitable for such exfoliation is challenging because of the intricate chemical processes involved. We present a theoretical approach for predicting 2D materials formed through chemical exfoliation under acidic conditions by identifying 3D materials amenable for selective etching. From a dataset of 66,643 3D materials, we identified 119 potentially exfoliable candidates, within several materials families. To corroborate the method, we chose a material distinctly different from MAX phases, in terms of structure and chemical composition, for experimental verification. We selectively etched Y from YRu₂Si₂, resulting in 2D Ru₂Si<i>_x</i>O<i>_y</i>. The high-throughput methodology suggests a vast chemical space of 2D materials from chemical exfoliation.