Development of microwave susceptors based on SiC composites and their application for a one-step synthesis of ZnO nanostructures

Abstract

We report on the synthesis of silicon carbide (SiC)-based composites containing different proportions of aluminum and/or vanadium III oxides. These composites have been successfully tested as susceptors into a commercial microwave oven operating at 2.45 GHz frequency. After 120 s only of microwave irradiation, the generated temperature has reached a plateau of 1750 °C, which was obtained for SiC composite containing 10 wt% of Al2O3 and/or V2O3. Furthermore, the structural properties of these composites were investigated by means of X-ray diffraction and scanning electron microscopy before and after exposure to microwaves irradiation. These SiC-based susceptors were then used as a source of heat to synthesize a nanostructured ZnO material through two different processes, namely the zinc metal evaporation/condensation occurring under air, and through a rapid thermal decomposition of zinc acetates and nitrates precursors. The structural analysis supported the possibility to grow nanostructures of controlled morphologies via the control of the microwave power and the type of precursor employed. We believe that this proposed one-step microwave assisted method provides a simple and efficient alternative to synthesize various oxide nanostructures in a very short reaction-time.