Controllable Electrochemical Synthesis of Ce⁴⁺-Doped ZnO Nanostructures from Nanotubes to Nanorods and Nanocages

The controllable electrochemical synthesis of Ce 4+ -doped ZnO nanostructures from nanotubes to nanorods and nanocages is reported. The electrochemical route for the preparation of Ce 4+ -doped ZnO nanostructures represents a simple, quick, and economical method. The growth mechanisms for Ce 4+ -doped ZnO nanotubes, nanorods, and nanocages are proposed here. Ce 4+ -doped ZnO nanotubes and nanocages formed when the crystal growth was only proceeded on the sides of six (101̅0) facets of a hexagonal planar nucleus with preferential growth in the (0001) direction. The hexagonal Ce 4+ -doped ZnO nanorods were formed when the crystal growth proceeded on the whole hexagonal planar nucleus with preferential growth in the (0001) direction. The X-ray diffraction, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and selected area electron diffraction were used to characterize the phase, composition, and qualities of the prepared Ce 4+ -doped ZnO nanotubes, nanorods, and nanocages. In addition, the photoluminescence properties of the prepared Ce 4+ -doped ZnO nanotubes, nanorods, and nanocages were investigated.