V2O5 nano-rods using low temperature chemical pyrophoric reaction technique: The effect of post annealing treatments on the structural, morphological, optical and electrical properties

Synthesis of high purity V2O5 nano-rods using chemical pyrophoric reaction process under the pyrophoric conditions has been demonstrated to successfully synthesis at 180 degrees C for 24 h. Their nanostructure has been characterized by XRD, HR-SEM, HR-TEM, XPS, UV, FT-IR, TG-DTA and I-V characteristics, respectively. XRD results confirmed that the complete conversion of as-prepared sample V4O9 phase changes to V2O5, for all annealing temperature. HRSEM and TEM studies shows that the V2O5 sample having dense, smooth and some random distribution of nano-rods at 600 degrees C. Standard oxygen peak 530.2 eV was found as expected for vanadium bonded oxygen in XPS spectrum. The decomposition process of this system is investigated by thermo-gravimetric and differential thermal analysis (TG-DTA). From I-V characteristics, the deviation of ohmic behavior at lower voltage range towards the non-ohmic at higher voltage range is due to the high voltage induced temperature effects in the sample. The conduction mechanism is discussed qualitatively on the basis of small polaron model. Activation energies have been found to be 0.45 eV at 600 degrees C for 1 h. (C) 2013 Elsevier Ltd. All rights reserved.