ZnO/SnO2 hierarchical and flower-like nanostructures: facile synthesis, formation mechanism, and optical and magnetic properties

Hierarchical and flower-like nanostructures with ZnO backbones and SnO2 branches were successfully prepared by electrodeposition (for ZnO nanorod arrays) and hydrothermal growth (for SnO2). The SnO2 nanorods grew epitaxially on the sides of ZnO nanorods. The morphologies and surface areas of ZnO/SnO2 hierarchical nanostructures can be tailored by changing the reaction time. Such hybrid ZnO/SnO2 nanostructures were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV-vis spectrophotometry and by using an accelerated surface area and porosimetry system (ASAP 2020M). A possible formation process and growth mechanisms for such hybrid ZnO/SnO2 nanostructures has been proposed based on series of time-dependent experiments. The UV properties show an enhanced as near-band gap emission compared with the primary ZnO nanorods. In addition, the magnetic properties of hierarchical ZnO/SnO2 nanostructures were also studied.