AC conductivity studies in copper decorated and zinc oxide embedded polypyrrole composite nanorods: Interfacial effects

In this work, synthesis, characterization and temperature dependent alternating current (AC) conductivity studies on copper decorated and zinc oxide embedded polypyrrole (PPy/Cu–ZnO) ternary composite nanorods are reported. The composite nanorods were prepared by mechanical mixing of chemically synthesized copper decorated polypyrrole (PPy/Cu composite) with zinc oxide (ZnO). The so prepared nanorods were thoroughly characterized using TEM, SEM, FTIR and XRD techniques. Significant morphological change in the form of solid nanorods of the ternary composite was confirmed from its TEM image. The surface morphology of the composite nanorods was shown to be porous hinting that these nanorods have good prospects for gas sensing applications. The AC conductivities of PPy, PPy/Cu composite and PPy/Cu–ZnO composite nanorods were studied in the frequency range 100 Hz to 5 MHz over a temperature range 303 K–373 K. The increased AC conductivity of the composite nanorods as compared to those of PPy/Cu composite and PPy is discussed on the basis of interfacial effects and supported theoretically on the basis of correlated barrier hopping (CBH) model.