Study Of Hydrogen Storage Capacity In Single-walled Carbon Nanotube

Hydrogen, as one of new type energy sources of low pollution, high efficiency, and cleanness, has a very broad application prospects. The point of hydrogen utilization is to look for the right materials to store hydrogen, and meet the needs of actual production. Molecular scale holes characterizing carbon nanotubes are of a relatively strong adsorption capacity, which shows its potential as a new type hydrogen storage material.Firstly, the author introduces the theoretical methods used in this paper:first principles calculations and Monte Carlo simulations. Secondly, theoretical calculations are carried out on the influences of several factors such as temperature, pressure, tube diameter, and tube spacing et al. on carbon nanotubes hydrogen storage performance, and main discoveries obtained include (i) variation pattern of the H2saturation adsorption pressure with the tube diameter and temperature;(ii) existence of extremum of the hydrogen storage capacity as a function of the tube spacing and tube diameter;(iii) diametrically opposite change of H2storage capacity with the tube diameter in different pressure domains;(iv) layered distribution of the H2adsorbed inside the tube. By combining the potential field information of carbon nanotubes-hydrogen with the arguments of liquid state theories, a theoretical mode is formulated for explaining self-consistently all of these new discoveries, and may serve to provide some guidance in improving the hydrogen storage capacity. Again, the author studies the adsorption behavior of gas in carbon nanotubes doped with transition metal, and it is shown that the gas is chemisorbed in the modified carbon nanotubes by a charge transfer occurring between the gas and the doped transition metal; consequently, a theoretical foundation for the nanometer gas sensor application is afforded.25Figures,4tables,125references.