Polythiophene-nickel (PT-Ni) nanocomposites have been prepared by the electrochemical oxidative polymerization of thiophene in the presence of nickel nanoparticles. The metallic nickel nanoparticles were obtained by the chemical reduction of nickel chloride with hydrazine at 100-130 degrees C. Poly(N-vinylpyrrolidone) (PVP) was used as protective agent in the synthesis of nickel nanoparticles. Transmission electron microscopy data revealed the particle size to be in the range 6-20 nm. X-ray diffraction, scanning electron microscopy, thermal analysis, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were utilized to characterize the nanocomposites. XPS measurements for the PT-Ni nanocomposites showed that the nickel content varied between 0.43 and 1.3 at.% in the PT-Ni nanocomposites. The electrical conductivity of the composites increased from 4.5 x 10(-3) Omega cm(-1) to 1.25 x 10(-2) Omega cm(-1) as the amount of nickel was increased from 0.43% up to 1.3%, polythiophene-Ni nanocomposites exhibiting a good electrical conductivity response. (C) 2015 Elsevier B.V. All rights reserved.