Effect of dip time on the electrochemical behavior of PPy-Cu(OH)2 hybrid electrodes synthesized using pyrrole and CuSO4

Abstract

Abstract The present work in on the successive ionic layer adsorption and reaction (SILAR) mediated synthesis and study of variations in electrochemical behavior of PPy-Cu(OH)2 hybrid electrodes with dip time. In the aqueous route preparation, 0.1 m pyrrole, 0.1 m CuSO4 dissolved in acidified water (using 0.5 m H2SO4) and H2O2 (30 wt %) were used as initial ingredient sources. The peaks observed in the X-Ray diffraction (XRD) pattern of the electrode at 2θ=21.500 oriented along the <110> planes closely match with the peaks of Cu(OH)2 as per JCPDS data card no. 42-0638 indicating the existence of triclinic Cu(OH)2 in the hybrid. The characteristic peak at 1559 cm−1 in the Fourier transform infrared (FTIR) spectrum due to pyrrole ring vibrations confirms the existence of PPy in the hybrid. Energy-dispersive X-ray (EDX) analysis shows the occurrence of C, N, O and Cu in the electrode material which substantiates the formation of the hybrid. The scanning electron microscopy (SEM) images of electrodes with optimum dip time (20 s) in pyrrole show networks of interconnected nanostructures. The specific capacitance increases with the dip time in the source solutions. The electrode prepared with optimum dip time in pyrrole has produced the maximum values of specific capacitance (SC), specific energy (SE) and specific power (SP) as 127.04 F/g, 44.16 Wh/kg and 30 kW/kg, respectively, when analyzed in 0.5 m H2SO4. Impedance study of the electrode explains the mixed capacitive nature and the maximum values of solution resistance (Rs), charge transfer resistance (Rct) and Warburg impedance (Rw) are 1.35 Ω, 143.4 Ω and 2.05 Ω, respectively.