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.

The effects of oxygen reactive ion etching (RIE) on the surface wettability of aligned carbon nanotube (CNT) films have been systematically investigated. It was found that 3 s of RIE treatment could change the surface of CNT films from hydrophobic to more hydrophilic. The degree of modification in the surface wettability of the film could be controlled by the flow rate of O2 gas during the RIE process. It is proposed that such a surface hydrophobicity change is related to the opened structure and functionalized tip of as-treated CNTs by oxygen reactive ions. More importantly, after the RIE treatment, focused laser pruning was utilized to trim the surface layer of treated CNTs and revert them back to a hydrophobic surface. Combined with the laser pruning technique and O2 RIE treatment, CNT templates with interlaced wettability surfaces in a stripe pattern have been fabricated. It has been demonstrated that this interlaced and structured wettability pattern can be used to selectively assemble microspheres or quantum dots on the aligned CNT films with desired patterns.

No abstract

No abstract