Controlled growth of uniform two-dimensional ZnO overlayers on Au(111) and surface hydroxylation
graphene-like ZnO, two-dimensional materials, hydroxylation, near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS), scanning tunneling microscopy (STM)
Ultrathin ZnO nanostructures present interesting two-dimensional (2D) graphene-like structure in contrast to wurtzite structure in bulk ZnO. Growth on Au(111) has been regarded as a well-established route to the 2D ZnO layers while controlled growth of uniform ZnO nanostructures remains as a challenge. Here, reactive deposition of Zn in O3 and NO2 was employed, which is investigated by scanning tunneling microscopy and X-ray photoelectron spectroscopy (XPS). We demonstrate that uniform ZnO monolayer nanoislands and films can be obtained on Au(111) using O3 and uniform ZnO bilayer nanoislands and films form on Au(111) using NO2, respectively. Formation of atomic oxygen overlayers on Au(111) via exposure to O3 is critical to the formation of uniform ZnO monolayer nanostructures atop. Near ambient pressure XPS studies revealed that nearly full hydroxylation occurs on monolayer ZnO structures upon exposure to near ambient pressure water vapor or atomic hydrogen species, while partial surface hydroxylation happens on bilayer ZnO under the same gaseous exposure conditions.
Tsinghua University Press
Hao Wu,Qiang Fu,Yifan Li,Yi Cui,Rui Wang,Nan Su,Le Lin,Aiyi Dong,Yanxiao Ning,Fan Yang,Xinhe Bao, Controlled growth of uniform two-dimensional ZnO overlayers on Au(111) and surface hydroxylation. NanoRes.2019, 12(9): 2348–2354