Nickel Oxide Decorated MWCNTs Wrapped Polypyrrole: One Dimensional Ternary Nanocomposites for Enhanced Thermoelectric Performance

Abstract

This study reports on a customized and revised approach to fabricate “nickel oxide decorated multi‐walled carbon nanotubes (MWCNTs) wrapped polypyrrole (PPy)” nanocomposite with enhanced room‐temperature thermoelectric (TE) properties. The nanocomposite is formed through three steps: MWCNTs functionalization via diazonium salt grafting of 5‐amino‐1,2,3‐benzene tricarboxylic acid; in situ generation on their surfaces of NiO nanoparticles with a homogenous distribution; the chemical polymerization of pyrrole using methyl orange as templating and dopant to wrap the MWCNTs‐(COOH)3‐NiO. Various techniques were used as characterization tools, including XRD, TEM, FTIR, Raman, TGA, XPS, and TE measurements. The PPy‐MWCNTs‐(COOH)3‐NiO nanocomposite exhibits significantly higher Seebeck coefficient, electrical conductivity, and power factor than PPy and PPy‐MWCNTs‐(COOH)3. The achieved enhancement in TE properties (figure of merit, ZTPPy‐MWCNTs‐(COOH)3‐NiO=1.51×10−2) is attributed to the presence of NiO, which acts as a dopant and improves the charge carrier density in the nanocomposite. These results offer the potential for waste heat recovery and large‐scale fabrication of high‐performance composites.