Adsorption behavior of CO2 molecule on AlN and silicene—application to gas capture devices

Abstract

Carbon dioxide contributes significantly to both global warming and climate change, processes that inflict major environmental damage, which is why it is of much interest to find a material that can adsorb carbon dioxide before it enters the atmosphere. In our study, we use first-principles calculations based on the density functional theory to investigate the adsorption of carbon dioxide on two-dimensional materials due to their unique chemical and physical properties. The two-dimensional materials we used include aluminum nitride, defected aluminum nitride, and silicene. We observed a negative adsorption energy of carbon dioxide on all three materials, signifying a spontaneous adsorption. Our charge analysis reveals a charge transfer from the materials to the molecule in addition to a significant overlap between the projected density of states spectra of the interacting atoms, all indicating the formation of chemical bonds between the material and adsorbed molecule. Our findings thus suggest that all the materials we used could be an effective adsorbent for carbon dioxide; however, the defected aluminum nitride sheet formed stronger bonds with carbon dioxide compared to the pure sheet. The application of our research could help decrease the world’s carbon footprint by creating devices to capture carbon dioxide before it enters the atmosphere.