Synthesis and thermal stability of ZnO nanowires

• Published in: Journal of thermal analysis and calorimetry Vol. 117; no. 2; pp. 635 - 642
• Main Authors: Awad, Madeha Ahmed, Ibrahim, Eslam Mohamed Mohamed, Ahmed, Ahmed Mohamed
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2014; Springer
• Subjects: Activation energy; Analysis; Analytical Chemistry; Annealing; Calorimetry; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Measurement Science and Instrumentation; Nanowires; Oxidation; Physical Chemistry; Polymer Sciences; Silicon substrates; Thermal stability; Zinc; Zinc oxide; Vapor transport; Annealing; ZnO NWs; Thermal stability
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-014-3836-x

ZnO nanowires (NWs) were synthesized on Au-coated Si (100) substrates by vapor transport method. The effect of high temperature annealing on the structural and chemical composition as well as thermal stability was studied. The as-prepared ZnO NWs was nearly stoichiometric and identified as hexagonal ZnO phase. After annealing at 1,473 K, the atomic ratio of O/Zn, the intensity of the diffraction peaks, and the diameter of nanowires were increased. The ZnO NWs were fragmented into nanocrystals and the fragments coalesced with each other after annealing at 1,673 K. The thermal stability of ZnO NWs was studied by thermo-gravimetric (TG) analysis. A sharp increase in the TG curves was observed and can be attributed to the oxidation of some possibly presented Zn atoms. The activation energy of oxidation of Zn interstitial atoms was found to be 484.81 kJ mol −1 . A mass gain peak was observed after annealing at 1,473 K, but it was completely eliminated after annealing at 1,673 K.