Structure of carbon nanospheres prepared by chlorination of cobaltocene: Experiment and modeling

Abstract

With the concourse of a variety of experimental techniques ͑neutron diffraction, x-ray photoelectron spectroscopy, 13 C nuclear magnetic resonance, electron microscopy, and Raman spectroscopy͒ and a combination of reverse Monte Carlo, molecular dynamics, and Monte Carlo simulations, we propose a model for the microscopic structure of a sample of carbon nanospheres obtained from chlorination of cobaltocene. The sample, which exhibits a high porosity, is shown to be formed by a series of interconnected sheets of graphene. Despite the large degree ͑Ϸ80%͒ of sp 2 hybridization shown by carbon atoms, there is a non-negligible amount of sp 3 -bonded carbons, some of them acting as links between graphene sheets. The transmission electron microscopy images simulated from the microscopic structure, which is extracted from the neutron diffraction data by a mixed reverse Monte Carlo-molecular dynamics/Monte Carlo procedure, agree remarkably well with the experimental results.

A molecular model for carbon black primary particles with internal nanoporosity

“…By using build units of carbon at various scales, detailed information of carbon structures can be gained from atomic to mesoscopic level. For instance, Reverse Monte Carlo (RMC) methods were extensively employed to retrace the atomic structures of carbon by comparison with several experimental measurements [34][35][36][37]. Beside the basic material properties, e.g.…”

“…Based on the knowledge gained from experiments, simulation methods have been widely developed to model and characterize the nanostructures of carbon [33][34][35][36][37][38][39][40][41]. There are mainly two types of modeling approaches to build structures of nanoporous carbon materials, namely reconstruction methods and mimetic methods.…”

Microscopic structure and dynamics of molten Se50Te50 alloys

“…This implies that the increase in entropy compensates the fact that the SeTe bonds are energetically favored with respect to SeSe and TeTe bonds. 11,13 This trends are summarized in Table II in which the partial averaged coordination numbers are collected. Here, one can also appreciate that, as temperature rises, the global coordination number increases slightly whereas the tendency to heterocoordination diminishes.…”

“…12 A recent study based on electron energy loss spectroscopy 13 seems to rule out the presence of compositionally ordered chains in the trigonal structure of solid Se 50 Te 50 .…”

The electrical transport properties of nitrogen doped carbon microspheres

“…Some of the shaped carbon materials that have been discovered since then include CNTs [10], CNFs [12], CNHs [13] and CNSs [14]. By far the most intensely studied of these has been CNTs due to their novel physical [15] and chemical [16] properties and many possible applications [17].…”