CO2 Capture by Metal-Decorated Silicon Carbide Nanotubes

Carbon dioxide (CO2) emission from continuously growing industries is one of the biggest global issues facing mankind as CO2 harms the environment and human health. To avoid the hazards of CO2, the development of materials for the efficient capture of CO2 is in high demand. Owing to the high surface area, nanotubes have a great potential for CO2 capture. In particular, silicon carbide nanotubes (SiCNTs) with large and partially heteropolar bonds are promising materials for CO2 capture, and extensive studies in this direction are needed. Here, a study on the CO2 capture behavior of metal (Cu, Pd and Ti) decorated SiCNTs using first principle calculations based on density functional theory is reported. The CO2 capture properties are investigated by calculations of band structure, the density of states (DOS), adsorption energy, and charge transfer. The findings show that CO2 adsorption on Cu-decorated SiCNT undergoes spontaneous exothermic reaction while the reactions are endothermic on Pd and Ti-decorated SiCNTs with notable change of the band structure and density of states of all nanotubes. Interestingly, analyses of adsorption energies show the chemisorptions of CO2 in Cu and Pd-decorated SiCNTs with high adsorption energies and the physisorption of CO2 in Ti-decorated SiCNT with low adsorption energy. The study underscores the potential of metal-decorated SiCNTs for efficient CO2 capture technology.