Growth and morphology of ZnO nanorods prepared from Zn(NO 3) 2/NaOH solutions

• Published in: Journal of the European Ceramic Society Vol. 26; no. 16; pp. 3745 - 3752
• Main Authors: Zhao, Juan, Jin, Zheng-Guo, Liu, Xiao-Xin, Liu, Zhi-Feng
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2006; Elsevier
• Subjects: Clusters, nanoparticles, and nanocrystalline materials; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Physics; Structure of solids and liquids; crystallography; ZnO nanorod; ZnO nanorod; Scanning electron microscopy; Basic solution; Rod; Zinc nitrates; XRD; Experimental study; High-resolution methods; Zinc oxides; Transmission electron microscopy; Supersaturated solution; Sodium Hydroxides; Chemical preparation; Growth from solution; Nanocrystal
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2006.01.006

ZnO nanorods on ZnO-coated seed surfaces were fabricated by a solution chemical method using supersaturated Zn(NO 3) 2/NaOH solution. The seed surfaces were coated on glass substrates by sol–gel processing and PEG addition. The mechanism of crystal growth and the factors affecting the rod growth were elucidated. The morphology and structure of both the seed surface and successive nanorods were analyzed by using SEM, XRD, TEM and SAED. Nucleation on the ZnO seed surface is crucial for rod growth since rods can only be observed on ZnO-coated substrates. Supersaturation is also required for rod growth and the Zn 2+ ion and NaOH concentrations must be varied synchronously to maintain the high level of supersaturation. The average diameter and length of the ZnO nanorods increase to different degree with increasing precursor concentration. The dependence of rod growth on temperature shows that the maximum rod growth rate at any given concentration of Zn 2+ occurs at a specific temperature, and the optimal temperature increases with Zn 2+ ion concentration. Densely thick nanorods oriented perpendicularly to the substrate can be obtained by controlling the seed surface with PEG assistance.