Advancement of Polyaniline/Carbon Nanotubes Based Thermoelectric Composites

Organic thermoelectric (TE) materials have been widely investigated due to their good stability, easy synthesis, and high electrical conductivity. Among them, polyaniline/carbon nanotubes (PANI/CNTs) composites have attracted significant attention for pursuing enhanced TE properties to meet the demands of commercial applications. In this review, we summarize recent advances in versatile PANI/CNTs composites in terms of the dispersion methods of CNTs (such as the addition of surfactants, mechanical grinding, and CNT functional group modification methods), fabrication engineering (physical blending and in-situ polymerization), post-treatments (solvent treatments to regulate the doping level and microstructure of PANI), and multi-components composites (incorporation of other components to enhance energy filtering effect and Seebeck coefficient), respectively. Various approaches are comprehensively discussed to illustrate the microstructure modulation and conduction mechanism within PANI/CNTs composites. Furthermore, we briefly give an outlook on the challenges of the PANI/CNTs composites for achieving high performance and hope to pave a way for future development of high-performance PANI/CNTs composites for sustainable energy utilization.

PANI coupled hierarchical Bi2S3nanoflowers based hybrid nanocomposite for enhanced thermoelectric performance

Bismuth sulfide (Bi₂S₃) is a promising material for thermoelectric applications owing to its non-toxicity and high abundance of bismuth (Bi) and sulfur (S) elements on earth. However, its low electrical conductivity drastically reduces the value of the figure of merit (ZT). In this work, we have synthesized three-dimensional (3D) hierarchical Bi₂S₃nanoflowers (NFs) by the hydrothermal route and further incorporated them with conducting polymer polyaniline (PANI) by simple chemisorption method. We have investigated the thermoelectric properties of the as-prepared Bi₂S₃NFs and PANI/Bi₂S₃nanocomposite samples and it is demonstrated that the incorporation of the PANI matrix with the 3D hierarchical Bi₂S₃NFs provides a conducting substrate for the easy transport of the electrons and reduces the barrier height at the interface, resulting in ∼62% increment in the electrical conductivity as compared to Bi₂S₃NFs. Moreover, a decrement in the thermal conductivity of the PANI/Bi₂S₃nanocomposite is observed as compared to pristine Bi₂S₃NFs due to the increased phonon scattering at the interfaces facilitated by the hierarchical morphology of the NFs. Furthermore, an increment in the electrical conductivity and simultaneous decrement in the thermal conductivity results in an overall ∼20% increment in the figure of merit (ZT) for PANI/Bi₂S₃nanocomposite as compared to pristine Bi₂S₃NFs. The work highlights an effective strategy of coupling 3D hierarchical metal chalcogenide with conducting polymer for optimizing their thermoelectric properties.

Silver embellished PANI/CNT nanocomposite for antimicrobial activity and sequestration of dye based on RSM modelling

Silver doped PANI/CNT (Ag-PANI/CNT) nanocomposite was synthesized and investigated as adsorbent for its possible application in the elimination of organic dye Brilliant Blue G (BBG). The morphological characteristics of Ag-PANI/CNT were studied using Fourier transform infrared, scanning electron microscopy, elemental mapping, transmission electron microscopy and X-ray diffraction. The response of operational parameters given as adsorbent dosage, concentration, pH and contact time for dye removal were investigated by using Response Surface Methodology (RSM). The results from RSM suggested that the efficiency of BBG elimination is 98.7 under the optimum conditions of experimental factors. The adsorption studies showed that the equilibrium data fitted well with Langmuir isotherm model compared to Freundlich. Finally, the antimicrobial activities of Ag-PANI/CNT were tested against bacterial strain Escherichia coli and Salmonella typhi and fungal strains Aspergillus niger.