Co-synthesis of ZnO–CuO Nanostructures by Directly Heating Brass in Air

ZnO–CuO nanostructures have been simultaneously synthesized by directly heating a CuZn alloy (brass) on a hotplate in ambient conditions. Depending on the Zn concentrations in the brasses, the dominant products transition from CuO nanowires to ZnO nanostructures. By changing the growth temperature and local Zn contents, 1D ZnO nanowires/nanoflakes, 2D ZnO nanosheets, and complicated 3D ZnO networks are obtained. Electron microscopy studies show that the as-synthesized ZnO nanoflakes and nanosheets are single crystalline. Based on “self-catalytic” growth, a tip-growth mechanism for ZnO nanostructures is discussed, in which the Cu in brass plays an important role to confine the lateral growth of ZnO. Finally, the electron field emission from the ZnO–CuO hybrid systems is tested for the demonstration of potential applications.