It can be concluded that the adsorption of cations on aluminum oxide is the result of contributions of both the HOMO and the LUMO orbitals. The adsorption of the anions is determined by the LUMO, HOMO-1, and LUMO+1 levels (B, D in Figure .1, S1.2) and is independent of the HOMO one. Let us continue our consideration of adsorption by studying a semiconductor as an example. As in the previous system, the alkali metal cations are strongly adsorbed on the graphene surface, the PyMe + cation is weakly bound to the surface. The E ads value for the cations on graphene decreases linearly as the ε HOMO value becomes lower (Figure ) and in case of E ads (ε LUMO ), the dependence (Figure ) is a volcanoshaped plot with an energy maximum in the region where ε LUMO ~ -0.10 a.u. At the minimum distance from the electrode are the compact alkali metal cations, whereas the farthest from the surface are the voluminous TPA + and TBA + ions. As the ε HOMO value becomes higher, the z 0 distance from the electrode increases exponentially (Figure ), and at an increase in the ε LUMO value, z 0 grows linearly ( , the highest energies are registered for some of the halides (Cl -, Br -), EtSO 3 -and i-PrCOO -.