Synthesis, characterization and electrochemical impedance spectroscopy of VOx-NTs/PPy composites

• Published in: Solid state communications 2010-10, Vol.150 (37), p.1807-1811
• Main Authors: Cui, Chaojun, Wu, Guangming, Yang, Huiyu, She, Shifeng, Shen, Jun, Zhou, Bin, Zhang, Zhihua
• Format: Article
• Language: English
• Subjects: A. Hybrid composites; A. Polypyrrole; A. VOx-NTs; Cationic; Charge transfer; Composite materials; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity of specific materials; Diffusion rate; E. Electrochemical impedance spectroscopy; Electrochemical impedance spectroscopy; Electronic transport in condensed matter; Electronics; Exact sciences and technology; Physics; Polypyrroles; Raw materials; Sol gel process
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2010.07.008

Composites consisting of vanadium oxide nanotubes (VOx-NTs) and polypyrrole (PPy) were synthesized by a two-steps method. VOx-NTs were firstly prepared by a combined sol–gel reaction and hydrothermal treatment procedure, in which V 2O 5 powder and H 2O 2 were used as raw materials and hexadecylamine as a structure-directing template. Then VOx-NTs/PPy composites were fabricated by a cationic exchange reaction between hexadecylamine and polypyrrole. The structure and morphology of the samples were investigated by SEM, TEM, XRD and FTIR techniques. The results confirmed that the template molecules were successfully substituted by the conducting polymers PPy without destroying the previous tubular structure. Electrochemical impedance spectroscopy (EIS) measurements were performed to evaluate the electrochemical kinetics of the samples. The results indicated that VOx-NTs/PPy composites had a lower charge transfer resistance and a faster lithium-ion diffusion speed than those of VOx-NTs, and the enhanced electrochemical kinetics could be attributed to the excellent electronic conductivity of polypyrrole.