Reduced graphene oxide (rGO) can improve the thermoelectric properties of polyaniline (PANI) by varying its concentration in composites of rGO nanosheets and PANI. The figure of merit (ZT) of rGO-PANI composites is increased with an increasing percentage of rGO (up to 50%), which is 7.5 times higher as compared to pure PANI. High resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analyses show a uniform growth of PANI over the surface of rGO as a template, leading to a more ordered structure with high crystallinity during polymerization. Compared to pure PANI, both the electrical conductivity and thermoelectric power of the rGO-PANI composite is higher due to the increased carrier mobility as confirmed by a Hall effect measurement. Fourier transform infrared spectroscopy (FTIR), ultra-violet visible range spectroscopy (UV-Vis) and Raman spectroscopy analyses reveal that strong p-p interactions assisted the uniform distribution of PANI on the rGO nanosheets. Other strong interactions include electrostatic forces and hydrogen bonding between rGO and PANI, which provide a route for constructing highly ordered chain structures with improved thermoelectric performance of PANI. There is no significant change in the thermal conductivity of the rGO-PANI composite as compared to pure PANI, which improves the thermoelectric performance of composite.

Conducting polymer‐chalcogenide composites have recently been used as propitious contenders for light‐weight, cost‐saving, and nonhazardous thermoelectric (TE) applications. In this work, polyaniline‐bismuth selenide (PANI‐Bi2Se3) nanoplate composites are fabricated via combining in situ oxidative polymerization and solvothermal method. X‐ray diffraction spectra illustrate a uniform growth of PANI matrix over Bi2Se3 nanoplates (BS NPs), directing toward a more ordered composite structure during polymerization. There is a reduction in average crystalline‐size, estimated from Williamson–Hall plot for the composite. Transmission electron microscopic and field emission microscopic images unveil the formation of two‐dimensional (2D) layered‐like structure of the composite. Fourier transform infrared spectra shows the interactions between the BS NPs along with the polymer chains by forming a 2D layered‐like composite structure. The enhanced transport properties can be elucidated on the basis of 2D variable‐range hopping model. The augmentation of power factor (S2σ) of the composite is nearly 30 times with an insignificant change in thermal conductivity (κ) as compared to PANI. This improves the high temperature TE performance (ZT = S2σT/κ~0.18) of the composite with 30 wt % BS NPs (ZTPANI~0.009). © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46887.

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