Thermoelectric Properties of Titanium Carbide Filled Polypyrrole Hybrid Composites

Transition metal carbides (TMCs) have attracted the attention of many researchers as promising thermoelectric materials due to their excellent electrical, thermal, and chemical properties. Titanium carbide (TiC), a compound of titanium and carbon, is a valuable member of the family of TMCs; however, studies on the thermoelectric properties of this material are limited. In the present study, the effects of the addition of TiC on the thermoelectric properties of polypyrrole (PPy) were investigated for the first time. Firstly, TiC-filled PPy hybrid composites containing different weight ratios of TiC (0.5%, 1%, 3%, 5%, and 10% with respect to polymer) were prepared by in situ oxidative chemical polymerization. The composites were characterized using Fourier transform infrared-attenuated total reflectance spectroscopy, ultraviolet-visible spectroscopy, Brunauer–Emmett–Teller and Barrett-Joyner-Halenda methods, x-ray diffraction, and scanning electron microscopy (SEM). The electrical conductivity measurements indicated that the electrical conductivity significantly increased in direct proportion with the increasing amount of TiC and the electrical conductivity of the pristine PPy increased from 0.8 Scm⁻¹ up to 160.2 Scm⁻¹ with the addition of 10% TiC. Furthermore, the addition of TiC led to increase in the power factor from 0.0115 μW m⁻¹K⁻² to 1.732 μW m⁻¹K⁻² which is approximately 150 times higher than the pristine PPy. This study indicated that the addition of TiC remarkably contributed to the TE properties of PPy.