Molecular modelling by DFT of 1,2-diaminoethane adsorbed on the Zn-terminated and O-terminated, anhydrous and hydroxylated ZnO (0001) surface

We found that DAE adsorbs tilted on the surface of dry Zn-ZnO, and the interaction consists of the combination of a Zn-N bond between the Lewis acid Zn and the amine base, and additional van der Waals interactions, while adsorption on the O-terminated and hydroxylated surfaces is parallel and occurs through the combination of van der Waals interactions and H bonds. At saturation, the surface coverage is 2.6 diaminoethane/nm2. The range in the energies of adsorption is Zn-ZnO (−0.52 eV) > O-ZnO (−0.45 eV) = HO-Zn-ZnO (−0.41 eV) > H-O-ZnO (−0.32 eV).