First-Principles Studies of Ethylene Oxide Adsorption on Pristine and Doped Graphenes

The adsorption interactions between ethylene oxide molecule (EO) and pristine graphene (PG), silicon- (SiG), aluminum- (AlG), and boron-doped graphene (BG) were studied using density functional theory (DFT) calculations to examine the potential applicability of the doped graphenes as EO gas sensors. The geometry optimizations and adsorption of EO on the PG and doped graphene have been done by using the 6-31G( d ) basis. The calculated adsorption energies ( E ad ) of EO on the PG, SiG, AlG, and BG corresponding to the most stable configurations were 0.54, –6.07, –24.55, and 0.50 kcal mol –1 , respectively, which revealed that the adsorption of EO on the SiG and AlG systems was much stronger than pristine graphene. For all the studied systems, band-gap energy ( E g ), chemical potential (μ), electrophilicity index (ω), the maximum amount of electronic charge (Δ N max ), molecular electrostatic potential (MEP) maps, Mulliken charge transfer, global hardness (η), and softness ( S ), were measured and discussed. Based on the acquired outcomes, the sensitivity of graphene-based chemical gas sensors for EO finding could be observably advanced through recommending the Al- and Si-dopants.