Methane adsorption on the surface of metal (Fe, Ni, Pd) decorated SWCNT: A density functional theory (DFT) study

Adsorption of methane gas on the catalytic systems comprising (8, 0) single walled carbon nanotube (SWCNT) decorated with transition metals (Fe, Ni, Pd) were investigated using plane-wave density functional theory. SWCNT was modified by adding these transition metals to both inside and outside the nanotube and replacing carbon atoms with them. All structures were relaxed and their structural and electronic properties were investigated before and after CH4 adsorption. The obtained results indicate that metal modified nanotubes exhibit good sensitivity and selectivity to methane. Adsorption energy results show that modifying nanotubes with Ni on the surface are more effective at adsorbing CH4 as compared to systems containing Fe and Pd atoms on the surfaces. CH4 adsorption on the surface of CNT decorated with transition metals changed both electronic and magnetic properties which show that these nanotubes are good candidate for detecting methane from the environment.