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We explore the adsorption characteristics and stability of lithium on silicene from first principles. Our work shows that lithium adsorption could provide a unique method for isolating a stable silicene-based material while inducing a bandgap. We explore the energetics, temperature dependent dynamics, phonon frequencies, and electronic structure associated with lithium chemisorption on silicene. Our results predict the stability of completely lithiated silicene sheets (silicel) in which lithium atoms adsorb on the atom-down sites on both sides of the silicene sheet. Stability is confirmed by molecular dynamics simulations conducted at elevated temperatures and real phonon frequencies for all k-values. Upon complete lithiation, the band structure of silicene is transformed from a zero-gap semiconductor to a 0.368 eV bandgap semiconductor. This new, uniquely stable, two-atom-thick, semiconductor material could be of interest for nanoscale electronic devices.

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Nanomaterials hold great promise for applications in thermal management and thermoelectric power generation. Defects are important as they can be either inevitably present during fabrication or intentionally introduced to engineer properties. Here, we investigate how thermal conductance responds to edge defects in narrow graphene, silicene, and boron nitride nanoribbons (NRs), from first principles using non-equilibrium Green's function method. Geometric distortions, phonon conductance coefficients, and local densities of states are analyzed. Hydrogen absences produce similar reductions in conductance in planar graphene and boron nitride NRs with larger reductions in buckled silicene NRs. Large atom vacancies affect all systems similarly. Emerging flexible and stiff scattering centers, depending on bond strengths, are shown to cause thermal conductance reduction. This knowledge suggests that inferences on unknown thermal properties of novel defected materials can be made based on understanding how thermal transport behaves in their analogues and how bond characteristics differ between the systems.

Thermodynamics of 2D nanomaterials exfoliation in solution are analyzed by considering parallel, perpendicular, and edge routes for graphene-oxide as an example. Multiscale modeling is used to quantitatively assess and compare free energy changes for various surface coverages.