Xue Wang1,2 Yong Ding1, Dajun Yuan3, Jung-Il Hong1, Yan Liu1, C. P. Wong1, Chenguo Hu2, and Zhong Lin Wang1 ()
View Author's information
1 School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA 2 Department of Applied Physics,3 Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332–0405, USA
Vertically aligned ZnO nanowires have been synthesized by a hydrothermal method. After being irradiated by a short laser pulse, the tips of the as-synthesized ZnO nanowires can be tailored into a spherical shape. Transmission electron microscopy revealed that the spherical tip is a single-crystalline piece connected to the body of the ZnO nanowire, and that the center of the sphere is hollow. The growth mechanism of the hollow ZnO nanospheres is proposed to involve laser-induced ZnO evaporation immediately followed by re-nucleation in a temperature gradient environment. The laser-irradiated ZnO nanowire array shows hydrophobic properties while the original ZnO nanowire array shows hydrophilicity. The as-grown ZnO nanowire arrays with hollow spherical tips can serve as templates to grow ZnO nanowire arrays with very fine
tips, which may be a good candidate material for use in field emission and scanning probe microscopy.