Effect of Dip-Coating Seed Layer on the Morphological and Optical Properties of ZnO Nanorods Growth by Hydrothermal Method

This paper presents the fabrication and characteristic analysis of ZnO nanorods grown on glass substrates using a two-step approach involving dip-coating for the seed layer and hydrothermal growth for ZnO nanorods. The study systematically investigates the effects of different dip-coating cycles using advanced characterization techniques to investigate the impact on the morphology, crystal structure, and properties of the nanorods, Incorporating field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) examination, and UV–VIS double-beam spectrometry. The ZnO nanorods exhibit a hexagonal morphology, with average diameters ranging from 60 to 450 nm through control of the dip-coating cycles. X-ray diffraction analysis reveals improved crystallinity with increasing dip-coating cycles. The UV transmittance spectra show characteristic absorption peaks in the UV range (360–380 nm) for all samples, with a decreasing band gap observed as the number of dip-coating cycles increases. These findings provide valuable insights into tailored ZnO nanorod synthesis and their potential applications in areas such as photocatalysis and optoelectronics. The study contributes to the fundamental understanding of nanomaterial properties, offering pathways for optimizing ZnO nanorod-based devices and technologies.