Aqueous Dispersion of Xenes by Liquid Phase Exfoliation of Monoelemental Crystals in Melamine Solution

Αfter the impressive evolution of graphene and its derivatives, a large number of two dimensional (2D) materials with important optical and electrical properties have been successfully fabricated. Liquid phase exfoliation (LPE) of layered and non-layered materials has become a widely applied method for the preparation of 2D nanostructures with an extensive variety of applications. However, in most cases organic solvents are used as liquid phase which are often toxic and environmentally unfriendly and lead to low yields. In this work, we present water as a suitable liquid phase and dispersion medium for the exfoliation of layered and non-layered monoelemental solids from IV_A, V_A and VI_A groups of the periodic table, such as silicon, tin, bismuth and tellurium. The 2D nanostructures, silicene, stanene, bismuthene and tellurene are therefore prepared by a completely sustainable and environmentally friendly method. The prepared Xenes, as they are called, are fully characterized by microscopic and spectroscopic techniques.