Effect of Refluxing Time on the Morphology of Pencil like Zinc Oxide Nanostructures Prepared by Solution Method

This paper presents the fabrication of pencil like zinc oxide nanorods by solution method using precursor zinc acetate di-hydrate (Zn(Ac)(2 center dot)2H(2)O) and alkali sodium hydroxide (NaOH) at a very low refluxing temperature (75 degrees C) for different ageing/ refluxing (12 h, 24 h, 36 h, 48 h and 60 h) time intervals. The morphological observation was carried out by using Field Emission Scanning Electron Microscopy (FESEM). The FESEM revealed that as the aging/refluxing time increased, the size (length and diameter) of the zinc oxide nanorods also increased. Furthermore, the morphology and crystallinity of the products grown were also confirmed by Transmission Electron Microscopy (TEM), high-resolution TEM, and Selected Area Electron Diffraction (SAED) patterns, which indicated that grown pencils grew along a [0001] direction with an ideal lattice fringe distance of similar to 0.52 nm. The optical properties of the grown pencil-like zinc oxide nanorods were characterized by using UV-vis spectroscopy. Strong absorbance peaks were observed at similar to 375 nm to 378 nm, which is the characteristic peak for the wurtzite hexagonal phase of ZnO. The FTIR spectroscopic measurement showed a standard peak of zinc oxide in the range of 428 cm(-1) to 520 cm(-1). Additionally, on the basis of chemical and morphological analysis, we have also proposed a possible growth mechanism for pencillike zinc oxide nanostructures.