Large-Scale Growth of a Novel Hierarchical ZnO Three-Dimensional Nanostructure with Preformed Patterned Substrate

Hierarchical nanostructures are of particular interest to researchers for their promising applications in functional materials. This work focused on the large-scale construction of 2-fold-symmetrical hierarchical ZnO nanostructure through wet-chemical route on preformed caky Zn substrate via the electroplating method. The result suggested that the preferential layer-by-layer dissolution of Zn plating, the in situ growth of ZnO nanowire arrays, and the gradual dissolution of the Zn substrate with the ongoing synthetic reaction jointly led to the growth of the hierarchical ZnO nanostructure. Meanwhile, the formation of the caky Zn substrate can be attributed to the spiral dislocation growth behavior of Zn plating and the existence of the precipitated H2 bubbles serving as the template. Multiple morphologies of such hierarchical ZnO nanostructure could be readily obtained not only by changing the synthetic conditions, but also by well-designing the structural parameters of the caky Zn substrate through controlling the electroplating conditions, including the employed cathode potential and the composition of the electrolyte.