A Molecular Dynamics Study on the Confinement of Carbon Dioxide Molecules in Carbon Nanotubes

The influence of atmospheric carbon dioxide (CO$_{2})$ concentration on global warming is considered as one of the primary environmental issues of the past two decades. The main source of CO$_{2}$ emission is human activity, such as the use of fossil fuels in transportation and industrial plants. Following the release of Kyoto Protocol in 1997, effective ways of controlling CO$_{2}$ emissions received much attention. As a result, various materials such as activated carbon, zeolites, and carbon nanotubes (CNTs) were investigated for their CO$_{2}$ adsorbing properties. CNTs were reported to have CO$_{2}$ adsorption capability twice that of activated carbon, hence they received the most attention. In the current study, single walled carbon nanotubes (SWNTs) were used as one dimensional nanoporous materials and their CO$_{2}$ adsorption capacity was analyzed with Molecular Dynamics simulations. Results indicated that SWNTs are excellent CO$_{2}$ adsorbers and their effectiveness increase at low CO$_{2}$ concentrations. In addition, we showed that by varying temperature, CO$_{2}$ can be removed from the SWNTs, providing a simple method to reuse SWNTs.