Polyaniline/graphitic carbon nitride/reduced graphene oxide ternary nanocomposite film for flexible thermoelectric...

The present study outlines the preparation of a ternary nanocomposite film comprising of polyaniline doped with camphor sulfonic acid (PANI), reduced graphene oxide (rGO), and graphitic carbon nitride (g-C₃N₄), and delves into its thermoelectric performance. PANI is known to possess high electrical conductivity (σ) and poor thermal conductivity (κ). However, its potential for thermoelectric applications is constrained by the low value of the Seebeck coefficient (S). The incorporation of g-C₃N₄in PANI has been demonstrated to result in an improvement of the Seebeck coefficient. Furthermore, the addition of rGO to the PANI/g-C₃N₄sample counteracts the decrease in electrical conductivity. The PANI/g-C₃N₄/rGO ternary nanocomposite film exhibits an enhanced Seebeck coefficient of ∼2.2 times when compared to the PANI sample. The Seebeck coefficient of the PANI/g-C₃N₄/rGO nanocomposite is enhanced by the energy filtering effect that occurs at the interfaces between g-C₃N₄/PANI and PANI/rGO. Theπ-πinteraction between the PANI chains and rGO is responsible for the increased electrical conductivity resulting from the well-ordered polymer chain arrangement on the g-C₃N₄and rGO surfaces. The ternary nanocomposite sample demonstrated a synergistic improvement in both electrical conductivity and Seebeck coefficient, resulting in a remarkable ∼4.6-fold increment in power factor and an ∼4.3-fold enhancement in the figure of merit (zT), as compared to the pristine PANI film.