Evaluation of constants of electron–phonon coupling between gas molecules and graphene

The adsorption of CO, NO, NO$_{2}$, Н$_{2}$О, and NH$_{3}$ molecules on ideal graphene and graphene doped with aluminum is analyzed using simple models. The constants of electron–phonon coupling are evaluated with the Lennard–Jones 6 – 12 potential for ideal graphene and the 2 – 4 potential for doped graphene. It is demonstrated that the dimensionless electron–phonon-coupling constant for ideal graphene is $\zeta\gg$ 1, while $\zeta\sim$ 1 corresponds to graphene doped with aluminum. Ways to use both types of graphene as a resistive gas sensor are discussed.