Tuning the structures of two-dimensional cuprous oxide confined on Au(111)
cuprous oxide, Au (111), scanning tunneling microscopy, confine
ABSTRACT Two-dimensional (2D) cuprous oxide (Cu2O) nanostructures (NSs) of monolayer thickness were synthesized on Au(111) and characterized using atomic-resolution scanning tunneling microscopy, X-ray photoelectron spectroscopy, and density functional theory (DFT) calculations. The surface and edge structures of 2D Cu2O were resolved at the atomic level and found to exhibit a graphene-like lattice structure. Cu2O NSs grew preferentially at the face centered cubic (fcc) domains of Au(111). Depending on the annealing temperature, the shapes and structures of Cu2O NSs were found to vary from elongated islands with a defective hexagonal lattice (mostly topological 5–7 defects) to triangular NSs with an almost-perfect hexagonal lattice. The edge structures of Cu2O NSs also varied with the annealing temperature, from predominantly the arm-chair 56 structure at 400 K to almost exclusively the zig-zag structure at 600 K. DFT calculations suggested that the herringbone ridges of Au(111) confined the growth and structure of Cu2O NSs on Au(111). As such, the arm-chair edges of Cu2O NSs, which are less stable than the zig-zag edges, could be exposed preferentially at 400 K. Cu2O NSs developed into the thermodynamically-favored triangular form and exposed zig-zag edges at 600 K, when the Au(111) substrate became mobile. The confined growth of 2D cuprous oxide on Au(111) demonstrated the importance of metal-oxide interactions in tuning the structures of supported 2D oxide NSs.
Tsinghua University Press
Qingfei Liu,Nannan Han,Shengbai Zhang,Jijun Zhao,Fan Yang,Xinhe Bao, Tuning the structures of two-dimensional cuprous oxide confined on Au(111). NanoRes.2018, 11(11): 5957–5967