Ultrafast microwave-assisted synthesis of various zinc oxide nanostructures

The conventional hydrothermal process for the synthsis of zinc oxide (ZnO) nanostructures is a slow process and provides less control in terms of shape, size and nucleation time. Whereas, synthesis through microwave heating takes only a few minutes to produce high quality, ultra-pure zinc oxide nanostructures. In this study, we present a protocol to fabricate various ZnO nanostructures (vertically-aligned nanorods, vertically-aligned nanowalls, nanoflowers and nanopillars) using a domestic microwave oven. Based upon the process study, variation in diameter and length of vertically aligned ZnO nanorods with growth time is reported. Uniformly distributed ZnO nanowalls along with ZnO nanoflowers are fabricated in less than 5 minutes. In addition to this, ZnO nanopillars are fabricated for the first-time using evaporation and degradation phenomena in the microwave oven. Furthermore, the ZnO nanorods are found to exhibit a superhydrophobic behaviour, whereas the ZnO nanowalls, nanoflowers and nanopillars are observed to have a hydrophobic behaviour. The developed ZnO nanostructures may find their applications in the areas of optics, electronics, biomedical, solar cell, sensors and transistors etc.