Microstructural study of assorted ZnO nanostructures: nanocombs, nanocones and microspheres

We report the microstructural study of ZnO nanostructures: nanocombs, nanocones and microspheres, synthesized using a simple thermal evaporation technique. While nanocombs require the presence of a catalyst, nanocones and hollow ZnO microspheres have been synthesized on silicon substrate in absence of any catalyst or template material. ZnO hexagonal nanocones have been synthesized on Si(100) substrates by directly evaporating zinc acetate dihydrate, at a low temperature of 400 degrees C, without using any carrier gas. The possible mechanism of formation of these structures has been discussed in brief. Chemical composition analysis by energy dispersive X-ray spectroscopy shows an O rich condition of ZnO nanocones and oxygen deficient condition of nanocombs.