Using ab initio DFT calculations we model the conductivity properties of porous nanocarbons and study the modifications upon modulation of their lattices with periodic arrays of nanopores or defects. We show correlations between different pore arrangements and conductivity properties of porous nanocarbons and built a unified model that can be used to predict their electronic properties [1,2]. The ab initio modeling of electron transport through defective regions in graphene revealed that its ultra-sensitivity to the molecular environment originates from a simultaneous opening or closing of local electron transport channels passing through the grain boundaries by the adsorbed analytes [3]. The analysis of the CO2 reduction process with the bulk MoS2 showed that its superior performance compared to nobel metals with a high current density and low overpotential in an ionic liquid originates from outstanding catalytic properties of the molybdenum terminated edges of MoS2 due to their metallic character, a high d-electron density and a low work function [4]. Using both semi-classical and strict quantum approaches we study the build-up of the electron correlations in extended electronic image states around highly polarizable metallic nanodisks. We describe the spatial properties and the effects of electron correlations in a model two-electron diskoid-like quantum system, develop semiclassical one-electron model of such diskotic systems and explain how the one-electron and many-electron solutions are related [5].

In the modeling of the self-assembly of dipolar nanoparticles we considered two distinct cases. First we model the stabilization of clusters and lattices of spherical particles with permanent electric or magnetic intrinsic dipole moment and weak van der Waals coupling. We found the parameters of nanoparticles at which these particles devoid of shape anisotropy form lattices with sh, fcc and hcp types of packing stable at room temperature [6]. Next we modeled the formation of helical superstructers out of anisotropic superparamagnetic magnetite nanocubic particles at the liquid-air interface in the presence of external magnetic fields. Both intrinsic and external degrees of freedom associated with fluctuating superparamagnetic dipole moment and motion of nanocubes in 3D space are considered. The formation of chiral assemblies is rationalized in terms of the interplay among van der Waals and magnetic dipole-dipole interactions, Zeeman coupling, as well as entropic forces. We have also identified a mechanism of the chirality amplification in the assembled structures [7]

[1] Baskin A., Král P. Electronic Structures of Porous Nanocarbons Scientific Reports 1, 36 (2011). [2] Wang B., Baskin A., and Král P. Porous Nanocarbons: Molecular Filtration and Electronics in Advances in Graphene Science, Edited by M. Aliofkhazraei, ISBN 978-953-51-1182-5, InTech, (2013). [3] Yasaei P., Kumar B., Klie R.F., Baskin A., Repnin N., Král P., Salehi-Khojin A. Chemical Sensing at Switchable transport Channels in Graphene Grain Boundaries (accepted in Nature Communications) [4] Asadi M., B. Kumar B., Pisasale D., Baskin A., Repnin N., Phillips P., Rosen B., Zhu W., Haasch R., Klie R.F., Král P., Abiade J., Salehi-Khojin A. Robust CO2 Reduction on MoS2 Edge (accepted in Nature Communications) [5] Baskin A., Sadeghpour H.R., and Král P. Correlated Diskoid-Like Electronic States (accepted in Scientific Reports) [6] Baskin A., Lo W.-Y., Král P. Clusters and Lattices of Particles Stabilized by Dipolar Coupling, ACS Nano 6, 6083 (2012). [7] Singh G., Chan H., Baskin A., Gelma E. Repnin N., Král P., Klajn R. Self-Assembly of Magnetite Nanocubes into Helical Superstructures (submitted)

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