Nickel sulfide-filled polyaniline hybrid composites for high-performance thermoelectric materials at room temperature

Abstract

Conductive polymer-based inorganic/organic composites are receiving increasing interest as potential options for lightweight, low-cost, and non-toxic room-temperature thermoelectric devices. In this study, nickel sulfide (NiS)-filled polyaniline (PANI) composites were synthesized, and their thermoelectric (TE) properties were investigated. XRD analyses showed the formation of the composites. Furthermore, XRD, FTIR, and UV-vis analyses proved the interactions between PANI and NiS. SEM-EDS analyses revealed that NiS particles were homogeneously distributed in the composite. Hall effect measurements revealed that the addition of NiS enhanced charge carrier concentration from 1.36 x 1020 cm-3 to 4.40 x 1020 cm-3 , resulting in an increase in pure PANI's electrical conductivity from 12.03 S/cm to 14 S/cm. Seebeck coefficient analyses showed a maximum value of 203 mu V/K for the composite containing 5 % NiS. The addition of NiS also increased the thermal conductivity of pure PANI from 0.14 W/mK to 0.42 W/mK. The highest power factor and ZT were calculated as 53.6 mu W/mK2 and 3.8 x 10-2. This study concluded that introducing NiS fillers into the conductive PANI matrix improves PANI's TE performance at room temperature.