Hydrogen interaction with carbon nanostructures

The synthesis of various new carbon nanomaterials, such as graphene and three dimensional fullerene solids has created much interest in scientific community, since it is assumed that these novel structures have many potential applications in the field of materials science. However, many important questions are still unanswered, varying from synthesis to interaction between adsorbents and carbon substrate. This thesis presents methods and results for simulations of a wide variety of carbon nanostructures of different dimensionalities: from zero dimensional fullerenes to three dimensional porous carbon structures. In order to simulate a wide range of different time scales, multiscale simulations, which combine ab initio density-functional theory calculations, classical molecular dynamics and the kinetic Monte Carlo method are performed. The focus of the thesis is on the structures which could have revolutionary applications in the future and to which the materials science community has built up great expectations. Functionalization of carbon materials via hydrogenation has recently attracted a lot of attention. Two main mainstream topics are: to modify electronic properties and/or to use the structure for hydrogen storage. For both of these, a profound knowledge of hydrogen interaction with the carbon structures is indispensable to be able to control the material properties. In this thesis, special attention has been paid to hydrogen interaction with carbon nanostructures and how hydrogen modifies the properties of these materials. Also, kinetic behaviour of hydrogen on the studied structures are investigated. The results presented in this thesis clarify hydrogen adsorption/desorption energetics on various carbon nanostructures and how hydrogen can be used as a tool to nano-engineer the electronic properties. In addition, several new carbon nanostructures found in our studies are presented. These novel structures have interesting properties and could be suitable for many applications.