Eur. Phys. J. Appl. Phys. (2015) 69: 30901
https://doi.org/10.1051/epjap/2015140441

Electronic thermal conductivity, thermoelectric properties and supercapacitive behaviour of conjugated polymer nanocomposite (polyaniline-WO₃) thin film

¹ Department of Physics and Astronomy, University of Nigeria, 40001 Nsukka, Nigeria
² National Centre for Energy Research and Development, University of Nigeria, 40001 Nsukka, Nigeria
³ UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies,University of South Africa (UNISA), Muckleneuk Ridge, PO Box 392, Pretoria, South Africa
⁴ Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape Province, South Africa

^a e-mail: ifeanyichukwuonline@yahoo.com

Received: 24 October 2014
Revised: 31 January 2015
Accepted: 13 February 2015
Published online: 12 March 2015

Abstract

A facile two-step, binder-free, chemical bath deposition (CBD) method was successfully employed in the synthesis of WO₃ nanograins onto the matrix of conjugated polymer (polyaniline). The X-ray diffraction (XRD) results showed that the nanocomposite retained monoclinic phase of WO₃ even when dispersed in polyaniline matrix. Owing to the synergistic effect offered by both the nanocomposite and structured metal oxide which may enhance the surface area, polyaniline-WO₃ nanocomposite exhibited good specific capacitance. Polyaniline-WO₃ yielded maximum specific capacitance ~96 F/g at scan rate of 5 mV/s in 0.5 M H₂SO₄ electrolyte. With the electronic thermal conductivity showing strong dependence on temperature, the estimated dimensionless figure of merit zT ~ 10⁻³ shows that the polymer nanocomposite (PNC) is promising as a new type of thermoelectric material. The electrochemical impedance spectroscopy showed that the PNC exhibited both pseudocapacitive and electric double layer capacitance behaviour.