Effects of heteroatoms on the electronic, sensor, and adsorption properties of graphene

详细

The effects of doping heteroatoms on the structure, electronic and adsorption properties of graphene are investigated using density functional theory calculations. Six different doped graphenes (with Al, B, Si, N, P, and S) are considered, and to obtain the interaction and adsorption properties, three sulfur-containing molecules (H₂S, SO₂, and thiophene) were interacted with selected graphenes. The adsorption energies (E_ad) in the gas phase and solvents show the exothermic interaction for all complexes. The maximum E_ad values are observed for aluminum doped graphene (AG) and silicon doped graphene (SiG), and adsorption energies in the solvent are not so different from those in the gas phase. NBO calculations show that the AG and SiG complexes have the highest E⁽²⁾ interaction energies and simple graphene (G) and nitrogen doped graphene (NG) have the least E⁽²⁾ energies. Population analyses show that doping heteroatoms change the energy gap. This gap changes more during the interaction and these changes make these structures useful in sensor devices. All calculated data confirm better adsorption of SO₂ by graphenes versus H₂S and thiophene. Among all graphenes, AG and then SiG are the best adsorbents for these structures.