First principles study of the atomic and electronic structure in graphene-fullerene hybrid systems

Abstract

The DFT study of atomic and electronic structure of the nanohybrid systems graphene-C 60 as the possible structural elements of graphite-like amorphous carbon formed by pulsed laser evaporation was performed. Various models of the interaction of C 60 fullerene fragments and whole fullerenes with single-layer graphene are considered. The mechanisms of adsorption, the local atomic structure, and the energy spectrum of the considered hybrid systems were studied in the framework of the Kohn-Sham method and the pseudopotential approximation. It is shown that depending on the orientation of the fullerene fragment, as well as on the distance of approach of this fragment relative to the sp 2-carbon plane the fragment can interact with graphene via physisorption mechanism, form different metastable structures, or form closed fullerene-like structures due to the formation of chemical bonds that integrate into the graphene sheet. In this work, we estimated the interatomic distances at the interfaces and the adsorption energy of fullerene fragments on graphene. The calculations showed that the electronic spectrum of the graphene-fullerene system with dispersion interaction in the interface was characterized by the superposition of the electronic states of the graphene sheet and the fullerene fragment separately, as well as by n-doping of the spectrum of this fragment. At the same time, it was demonstrated that the electronic energy spectrum of the integrated structures significantly differed from the spectra of pure graphene as well as С 60 , and was characterized by sp 2-and sp 3-hybridized carbon. The comparison of the calculated graphene-½C 60 spectra with graphene and graphene-C 60 DOS as well as with experimental electron energy loss spectrum of the C 60 and with the differential tunneling current-voltage characteristic of the system graphene / С 60 / Cu was performed. Satisfactory fit was obtained for the calculated data and the experiment.

The adsorption modeling of bisphenol A derivatives on the surface of carbon materials

“…Two exchange-correlation functionals were used for comparison: PBE (Perdew, Burke and Ernzerhof) [21] based on the generalized density gradients approximation with taking into account the Grimme DFT-D2 [22] empirical correction and the BH (Berland and Hyldgaard) [23] functional developed to account for weak van der Waals interactions. The use of the empirical Grimme correction is a common practice in modeling intermolecular interactions [13,24]. This is due to the fact that the popular PBE functional does not describe weak Van der Waals interactions well.…”

Effect of the Structure Morphology on the Mechanical Properties of Crumpled Graphene Fiber

“…Graphene, a well-known twodimensional material, gave a fresh concept for new three-dimensional (3D) structures with complex architecture fabricated on the basis of graphene [2][3][4]. Carbon structures with unique electrical, mechanical, and thermal properties are of great interest today [5][6][7][8][9][10][11]. Recently, considerable attention has been paid to graphene fibers, a new type of carbon fiber consisting of many monolayers of wrinkled and crumpled graphene sheets [12][13][14][15][16][17].…”

Estudio de las propiedades de adsorción de un sistema formado por Grafeno + Semifullereno (C₃₀) decorado con diferentes metales

“…Mediante el método de Kohn-Sham y la aproximación de pseudopotenciales se ha estudiado el mecanismo de adsorción obteniendo resultados que muestran que dependiendo la orientación de los fragmentos de fullerenos como la distancia de interacción respecto al plano de carbono sp 2 , dichos fragmentos pueden interactuar con el grafeno a través de mecanismos de fisisorción, formar distintas estructuras metaestables o formar fullerenos cerrados debido a la formación de enlaces químicos que se integran a la capa de grafeno. Los cálculos además mostraron que el espectro de energía de estas estructuras difería significativamente de los espectros del grafeno puro y del C 60 caracterizado por hibridación sp 2 y sp 3 [21]. La formación de estas nanoestructuras hibridas, grafeno fullerenos, tambien han sido respaldadas por estudios de simulación que contemplan técnicas de simulación de dinámica molecular los cuales han demostrado la formación de estos nanocompuestos abriendo la puerta a futuras aplicaciones biológicas y tecnológicas [8].…”