▎ 摘　　要

The interaction of sulfuric acid molecules with bilayer graphene both adsorbed outside and intercalated inside the bilayer is studied using density functional theory (DFT) calculations. Equilibrium configurations, electron transfers, binding energies, and densities of states are presented for different acid concentrations both inside and outside the bilayer. For low concentrations adsorption is preferred over intercalation, but when the acid molecules form a complete monolayer both sorptions are energetically equivalent. The intercalation of acid molecules separates the two layers, decoupling their electronic behavior, and the system becomes a zero band gap semiconductor like monolayer graphene. The intercalation of the acid reduces the interaction between the two graphene layers. This explains the surfactant effect of sulfuric acid on graphitic nanostructures, which, for instance, helps to exfoliate graphene layers from graphite and to separate the nanotubes of a bundle.