Structure and stability of Molybdenum Sulfide Fullerenes

Atomic models of MoS-based nanoparticles with fullerene-like structures were constructed. Their stability and electronic properties with respect to the particle size and composition have been investigated for the first time using the DF-TB method. The present calculations and MD simulations show that stoichiometric single-walled moS2 fullerenes with octahedral shape are unstable, at least up to sizes of several hundreds of atoms. The instability is attributed to the high strain energies at the corners of the MoS2 nanooctahedra. However, the particles are considerably stabilized if local deviations from the stoichiometry is allowed at the corners. An additional attractive inter-layer interaction enhances this trend, such that multi-wall nanooctahedra with sizes between thousand and ten thousand atoms are stable species, which can be observed experimentally. Larger nanooctahedra are transformed into multiwall particles with a spherical shell.