Making adjustable two-dimenasional (2D) materials is an emerging route to reach a superior control of new functinal properties. Consideration will be given here to two distinct cases in this respect. On one hand is the case of the epitaxial Xenes, an emerging class of 2D monoelemental lattice; on the other hand is the morphology design of MoS2 nanosheets with an anisotropic fashion. By close analogy with graphene, epitaxial Xenes are comprised of monoelemental atoms arranged in a honeycomb lattice; unlike graphene, Xenes are epitaxially grown on substrates and exhibit a varying degrees of buckling and/or puckering in the lattice structure. Examples in this respect are silicene, germanene, stanene, borophene, epitaxial phosphorene, and recently synthesized antimonene and tellurene. Buckling in Xenes can be taken as a leverage to tune the electronic and quantum properties (see the pictorial sketch of a buckled Xenes with topologically protected edge states in Figure, top). Indeed, the electronic state of epitaxial Xenes can range from topological insulators to trivial insulators, semiconductors, semimetals, and metals, depending on the configurational details (e.g. buckling, substrate, chemical functionalization, and strain); and topological transitions among these electronic states are predicted to take place as a function of an external solicitation (e.g. vertical electric field, applied stress).  An overview of the state-of-the-art on the epitaxial Xenes and of their potential in nanoelectronics will be given. Silicene transistors will be shown as a case in point in this respect. 

A different case of morphology design at the 2D level is based on the chemical vapour deposition of MoS2 nanosheets on one-directional structured substrates. The highly conformal character of the MoS2 growth allows for the achievement of an anisotropically modulated MoS2 nanosheet where the phonon and electronic properties are observed to be strongly morphology dependent (see sketch in Figure, bottom). The so-induced anisotropy in the MoS2 nanosheet morphology results in a light polarization dependent Raman spectrum and periodic charge fluctuations. Implications on the band-gap and strain engineering will be discussed, and the potential for applications envisioned with the aim of proposing a new nanotechnology platform for anisotropy at the 2D level by design.