First principles investigation of oxygen adsorptions on hydrogen-terminated ZnO graphene-like nanosheets.

The structures of ZnO graphene-like nanosheets (ZnOGLNS), i.e., ZnO aromatic-like (AL-ZnONS), naphthalene-like (NLL-ZnONS), pyrene-like (PRL-ZnONS), coronene-like (CNL-ZnONS) and circumcoronene-like (CCL-ZnONS) and their oxygen adsorptions were obtained using the B3LYP/LanL2DZ method. Adsorption energies of O(2) on AL-ZnONS, NLL-ZnONS, PRL-ZnONS, CNL-ZnONS and CCL-ZnONS are reported. The bond strengths of the most inner Zn-O bonds of ZnOGLNSs are in order: CCL-ZnONS > CNL-ZnONS > PRL-ZnONS. It was found that chemisorptions of O(2) occur on the hydride atoms of zinc-hydride in the ZnOGLNSs. Physisorptions of O(2) only occurring over the plane of ZnOGLNS were found. All the ZnOGLNSs are oxygen sensitive materials and would be developed to be oxygen sensor based on electrical conductivity.