DFT Studies of Ethylene Oxide Adsorption on Pristine and Ga-doped Carbon Nanotubes

Adsorption of ethylene oxide (EO) on the endo- and exo-surfaces of (9,0) and (12,0) zigzag pristine carbon nanotube (CNT) and gallium-doped CNT (CNT-Ga) was investigated using density functional theory (DFT) at M06-2X/6-31++1G** level. The enhanced sensitivity of CNT-Ga towards EO molecule associated with adsorption energies (Ead), Fermi energy level (Ef), band gap energy (Eg), Eg change (ΔEg) and molecular electrostatic potential (MEP) were calculated and comprehensively analyzed. According to the obtained results, the (9,0) CNT-Ga showed superior sensitivity toward EO and it will be useful in fabrication of new EO gas sensing devices.