ZnO nanotube arrays and nanotube-based paint-brush structures: A simple methodology of fabricating hierarchical nanostructures with self-assembled junctions and branches

ZnO nanotube arrays and self-assembled hierarchical nanostructures. are reported here. The ZnO nanostructures were synthesized on Zn foils by a simple solvothermal approach. The hierarchical nanostructures resemble the paint-brush morphology, which consisted of a bunch of self-assembled thin nanowires on a comparatively thick ZnO nanotube wall. Successful creation of surface roughness through controlled etching of the ZnO nanotube walls provided the secondary nucleation centers for the nanowires.