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

Abstract

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.