High-performance thermoelectric materials based on ternary TiO₂/CNT/PANI composites

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Organic thermoelectric materials offer potential for flexible and low-cost energy harvesting.
• Carbon nanotube (CNT)/polyaniline (PANI) composites show promise but require further optimization for high performance.
• Titanium dioxide (TiO2) nanoparticles can influence charge transport and scattering mechanisms in composites.

Purpose of the Study:

• To fabricate and characterize high-performance thermoelectric materials using TiO2/CNT/PANI ternary composites.
• To investigate the effect of TiO2 incorporation on the thermoelectric properties of CNT/PANI binary composites.
• To optimize the thermoelectric performance through material composition and processing conditions.

Main Methods:

• Fabrication of TiO2/CNT/PANI ternary composites.
• Characterization of electrical conductivity and Seebeck coefficient.
• Optimization of material composition (e.g., TiO2 content, CNT/PANI ratio) and processing parameters (water treatment, temperature).

Main Results:

• Achieved a conductivity of ~2730 S cm-1 for CNT/PANI binary composites (highest reported for CNT/PANI).
• Enhanced Seebeck coefficient in ternary TiO2/CNT/PANI composites due to lower carrier density and improved energy scattering at interfaces.
• Obtained a high thermoelectric power factor of 114.5 μW mK-2 for a specific ternary composite composition (30% TiO2/70% (a-CNT (70%)/PANI (30%))), the highest reported for PANI-based ternary composites.
• Demonstrated further optimization through water treatment and processing temperature tuning.

Conclusions:

• The incorporation of TiO2 nanoparticles is an effective strategy to enhance the thermoelectric performance of CNT/PANI composites.
• Judicious tuning of carrier concentration and electrical conductivity via TiO2 addition is key to improving the power factor of organic thermoelectric materials.
• The developed TiO2/CNT/PANI ternary composites represent a significant advancement in high-performance organic thermoelectrics.