Theoretical study on the adsorption behaviors of H2O and NH3 on hydrogen-terminated ZnO nanoclusters and ZnO graphene-like nanosheets

The structure optimizations of all configurations of H2O and NH3 adsorbed on ZnO nanoclusters (ZnONCs), aromatic-like (AL-ZnONC), naphthalene-like (NLL-ZnONC), pyrene-like (PRL-ZnONC) and ZnO graphene-like nanosheets (ZnOGLNSs), coronene-like (CNL-ZnONS) and circumcoronene-like (CCL-ZnONS) were carried out using the B3LYP/LanL2DZ calculations. Adsorption energies of H2O and NH3 on AL-ZnONC, NLL-ZnONC, PRL-ZnONC, CNL-ZnONS and CCL-ZnONS are reported. It was found that the H2O adsorptions on the nanoclusters (ZnONCs) and nanosheets (ZnOGLNSs) are caused by interactions between (1) water oxygen and Zn surface atom, (2) water hydrogen and hydride hydrogen of the surface and (3) water hydrogen and oxygen surface atom. For the NH3 adsorptions occur by pointing its nitrogen toward Zn surface atom and this orientation is somewhat perpendicular to the surface planes of ZnONCs and ZnOGLNSs.