Enhancing Thermoelectric Properties of p-n Hybrid Composites: A Statistical Approach Using Response Surface Methodology (RSM) and 1D Nano-Structuring Model

Thermoelectric applications have sparked significant interest in organic–inorganic hybrid composites. In this research, the optimal experimental parameters of a p-n (polypyrrole–titanium oxide) thermoelectric formulation material are identified using the response surface technique (RSM), which is based on the central composite model (CCD). The relationship between the three investigated parameters, including electrical conductivity (σ), thermal conductivity (κ) and Seebeck coefficient (S), was modelled by a polynomial equation of the second order. Then, the titanium dioxide spherical particles are given a nanotube structuring process, which results in an even better composite. Additionally, 1D model ternary hybrid composite based on the inclusion of carbon nanotubes was made, resulting in an improvement of three-order magnitude of the merit coefficient ZT = 9.69 × 10^–4. Transmission electron microscopy (TEM) evaluation revealed the successful of the CNT/PPy nanocomposites external walls decoration through an intimate contact with the formed TiO₂ nanotubes.