Synthesis and electrolytic cation-dependent cyclic voltammetric study of SILAR deposited PPy-Cr2O3 in equimolar aqueous solutions of H2SO4, Na2SO4, and K2SO4

Abstract

PPy-Cr 2 O 3 hybrid flexible electrodes (HFEs) have been synthesized by successive ionic layer adsorption and reaction (SILAR) method using flexible aluminum (Al) strips (derived from cold drink cans) as substrates. For the synthesis, 0.1 M pyrrole and 0.02 M K 2 Cr 2 O 7 dissolved in 0.5 M aqueous H 2 SO 4 were used as precursors while the flexible aluminum strips derived from waste cold drink cans were used as substrates. XRD pattern shows the peak at 50.48• indicating the existence of rhombohedral Cr 2 O 3 in the hybrid. FTIR spectrum corroborates the formation of hybrid. SEM image exhibits porous morphology with interconnected granules. TEM image depicts the Cr 2 O 3 granules of average size 20 nm and PPy globules of average size 50 nm. The liquid-solid contact angle was found to be 10• 30′ indicating the near-superhydrophilic nature of HFE. Cyclic voltammetric (CV) analyses of HFEs have been carried out in each of 20 ml, 0.5 M solutions H 2 SO 4 , Na 2 SO 4 , and K 2 SO 4 . Changes in potential window, redox behavior and hence, the specific capacitance have been observed. The pseudocapacitance of HFE is combined effect of doping-dedoping of PPy matrix with SO 4 2− anions as well as redox reaction shown by Cr 2 O 3 . HFE shows maximum specific capacitance 4246 Fg −1 in K 2 SO 4 as measured from CV. HFE shows appreciable stability with 58.20% retention in capacitance even after 1000 cycles.

Study on the Crystallinity and Oxidation States of Nanoporous Anodized Tin Oxide Films Regulated by Annealing Treatment for Supercapacitor Application

“…The charge transfer diagram is shown in Figure . Electrolyzed ions have a great influence on capacitor storage. , Tin oxide involves two charge storage mechanisms. − One is the oxidation and reduction of tin ions by ion intercalation/delamination in solution The second is that ions are adsorbed/desorbed on the surface of tin oxide The shapes of the curves were very different from the behavior of EDL capacitors with a distinct redox peak, which indicated the main contribution of pseudocapacitance. At the same time, the differences in CV curves were evident at different annealing temperatures.…”

“…Therefore, complex combinations with inorganic materials (metal oxide/hydroxide, etc.) are applied to solve this problem. − For metal oxide electrode materials, due to the high pseudocapacitance characteristics and excellent electrochemical stability, they have become the most concerned electrode materials today. Researchers have done a lot of studies on the electrochemical properties of metal oxides such as TiO 2 , RuO 2 , NiO, V 2 O 5 , MnO 2 , Fe 2 O 3 , and Co 3 O 4 . − Due to the multivalent states of these metals, they can undergo multiple redox transitions between electrolyte ions and materials, thereby enhancing pseudocapacitance behavior.…”

Structural and electrochemical study of hybrid flexible electrodes containing in-situ growth of RuO2 within PPy matrix controlled by RuCl3 % consumed during SILAR synthesis for preparation of symmetric device

“…Even though it has these advantageous features, PPy suffers from poor electrochemical stability in electrolytes, the lower elasticity of volume during the doping and dedoping process, fragility in the flexible devices. These inadequacies can be eliminated either by forming copolymers of pyrrole [10][11][12][13], or by forming PPy composites/hybrids [14][15][16][17][18][19][20][21][22] to ameliorate the optical and mechanical properties, stability and processability.…”