Investigation of Charge Transport in Thermoelectric Power Generation Performance-Based Nanocomposite of PEG-Coated Nanostructured NiO Synthesized in Ionic Liquid

This study aims to develop high-performance hybrid nanocomposites for solid-state energy conversion. We achieved this by improving charge transport and thermoelectric efficiency through the interaction of polymers, nanoparticles, and ionic liquids. Nickel oxide nanoparticles (NiO NPs) were synthesized via a sonochemical route using a novel ionic liquid, 1,2-(propan). In our recent work, this approach enabled the formation of a hybrid [NiO NPs + IL] system, which was subsequently incorporated at different loadings (8, 15, and 30 wt.%) and coated with polyethylene glycol (PEG). The resulting nanocomposites were investigated to elucidate charge-transport mechanisms and assess the influence of the polymer coating on their optical, electrical, and thermal transport properties. Optical measurements showed a shift in the band gap due to π–π* electronic transitions. This effect indicates strong interface interactions. The PEG-coated [NiO NPs + IL] nanocomposites exhibited significantly enhanced charge-carrier mobility, resulting in improved electrical conductivity. Remarkably, a high Seebeck coefficient of 720 μV/K and an electrical conductivity of 0.35 S/cm were achieved, resulting in a maximum power factor of 24.74 μW/m·K2, surpassing many recently reported polymer-based nanocomposites. PEG-coated [NiO NPs + IL] systems offer tunable optical properties and superior thermoelectric performance. Consequently, they are a promising alternative to conventional nanocomposites for sustainable energy conversion.