Influence of refluxing time and HMTA on structural and optical properties of rod, prism like ZnO nanostructures

By this report, we described the facile synthesis technique for the synthesis of hexagonal prism and rod like ZnO nanostructures via simple refluxing route by varying the hexamethylenetetramine and refluxing time. The microstructural parameters such as unit cell volume, bond length, dislocation density and microstrain were extracted from the X-ray diffraction data analysis. The variation in size, shape and morphological details of the prepared nanostructures were discussed using the scanning electron microscope and transmission electron microscope images. The effect of precursors concentration ratio and variation in refluxing time, which played a significant role on the formation of ZnO nanostructures, on the tunability of the aspect ratio was discussed. Also, in relation with these parameters the variation of the band gap and the intensity of (photo luminescence) emission of the nano ZnO was discussed. The obtained results revealed that the microstructural parameters, band gap and luminescence are highly depending on the aspect ratio and the morphology of the ZnO nanostructures. The variation of phonon modes with crystallinity and the phonon life time of the prepared nanostructures were discussed with the Raman spectral data analysis. The photocatalytic activity of the prepared nanostructures with different morphology (prism, rod and bipods) was monitored.