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We present extensive pseudopotential density functional theory calculations dedicated to analyze the adsorption properties and migration behavior of hydrogen on C 60 -supported Pt n (n = 1, 2, 5, 13) clusters. When adsorbing Pt species on C 60 , we find that the systems gain energy when the platinum atoms aggregate on the fullerene surface, forming clusters of different sizes and symmetries. Notable structural variations around the adsorption sites are obtained, consisting in expansions and contractions of the C−C, Pt−Pt, and Pt−C bond lengths as large as 7%. The adsorption energies vary in the range of 1.5−3.1 eV, and there is a notable Pt → C charge transfer (∼0.15e) that leads to the formation of robust Pt−C bonds. When the C 60 Pt n compounds are exposed to molecular hydrogen, the Pt-rich regions of the surface are the ones favorable for the dissociative chemisorption of H 2 . The density of states around the Fermi level is very sensitive to the presence and location of the hydrogen species in our C 60 Pt n structures, a result that could have strong effects on the transport properties of our fullerene compounds and can be used as a fingerprint to identify precise structural features in these kind of complexes. Using the nudged-elastic-band method, we obtain that atomic hydrogen diffuses very easily on the surface of both free-standing and C 60 -supported Pt n clusters. However, H-atom migration on the carbon surface is very unlikely, since barriers of the order of 1.5 eV need to be overcome. Hydrogen transfer events between platinum and carbon regions on our here-considered C 60 Pt n structures, so-called spillover processes, are highly dependent on the local atomic environment. When going from the single Pt atom to the small cluster regime, the spillover energy barriers vary between 0.7−1.6 eV, a result that is important to consider in order to more clearly understand recent experimental studies addressing hydrogen storage in carbon nanostructures via chemical adsorption.

Electronic redistribution triggered by an external electric field pointing along nanowires axis is an important issue due to its potential applications. Few researchers have addressed this problem because when realistic sizes and doping levels are considered, the many-body electron–electron interactions becomes highly complex. In this contribution, we present a systematic study of the effect of such an electric field on micrometer-long GaAs/AlGaAs nanowires with n-doping levels around 1018 electrons/cm3. Our method is based on the derivation of a real-space effective potential that considers a Yukawa-like electronic interaction. One of our most important findings is related to the spatial stability of the Wigner molecule under the external field, where the electronic charge is displaced on pinning positions. This discovery is very promising for the realization of valuable architectures based on the quantized electronic distributions in technological areas such as nanoelectronics or spintronics or as electric sensors at the nanoscale.