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.