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

Abstract

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.