Molecular Dynamics Study Of Hydrogen Physisorption In Carbon Nanotubes

The significance of studying hydrogen storage in carbon nanotubes (CNTs) is introduced firstly, and the CNTs as a promising material for hydrogen storage are indicated.Secondly, the recent international advances on hydrogen storage in CNTs and the main productions of theoretical and experimental researches are summarized completely. And then, we introduce three primary methods of theoretical study on hydrogen storage in CNTs: 1. Grand Canonical Monte Carlo (GCMC) method based on all kinds of interaction potentials. 2. Classical Molecular Dynamics (MD) method based on all kinds of interaction potentials. 3. Density Function Theory (DFT) based on quantum theory.Thirdly, by adopting Lennard-Jones (L-J) potential model and MD method, we build a MD simulation cell, which contains the information of a Grand Canonical Ensemble (GCE), and the elastic collision mechanism, and then simulate the process of hydrogen physisorption in single walled carbon nanotube (SWCNT). The relationships between hydrogen storage capacity of SWCNT and temperature, pressure, SWCNT's diameter are studied systemically. Through analyzing the adsorption isotherms obtained at the different temperatures and different SWCNT's diameters, we found that at high pressure and low temperature, increasing the SWCNT's diameter properly, will be in favor of hydrogen storage. Comparing results obtained by us, GCMC and DFT indicate that the MD method presented in this paper for GCE simulation is correct and feasible. That is this method can be used in GCE widely.At last, the whole article is summarized and some expectations of further MD study on hydrogen storage in carbon nanotube array are also given.