Note that the strong electrostatic contribution was also documented in experimental studies of arsenic-phosphorene complexes due to the low adsorption heat in variable temperature experiments . Electrostatic driving forces have also been described as the main stabilizing contribution for the covalent and non-covalent adsorption of formaldehyde and heavy metals [e.g., Pb(II), Hg(II), and Cd(II)] onto phosphorene .