Two-Dimensional CVD-Graphene/Polyaniline Supercapacitors: Synthesis Strategy and Electrochemical Operation

Abstract

Nanocomposites of graphene materials and conducting polymers have been extensively studied as promising materials for electrodes of supercapacitors. Here, we present a graphene/polyaniline heterostructure consisting of a CVD-graphene and polyaniline monolayer and its electrochemical operation in a supercapacitor. The synthesis employs functionalization of graphene by p-phenylene sulfonic groups and oxidative polymerization of anilinium by ammonium persulfate under reaction conditions, providing no bulk polyaniline. Scanning electron microscopy, atomic force microscopy, and Raman spectroscopy showed the selective formation of polyaniline on the graphene. In situ Raman spectroelectrochemistry and cyclic voltammetry (both in a microdroplet setup) confirm the reversibility of polyaniline redox transitions and graphene electrochemical doping. After an increase within the initial 200 cycles due to the formation of benzoquinone−hydroquinone defects in polyaniline, the specific areal capacitance remained for 2400 cycles with ±1% retention at 21.2 μF cm −2 , one order of magnitude higher than the capacitance of pristine graphene.

Chemical vapor deposited graphene-based quasi-solid-state ultrathin and flexible sodium-ion supercapacitor

“…The specific areal capacitance of the fabricated flexible SCs was obtained as 15.3 mF cm -2 at the current density of 0.05 mA cm -2 . To the best of our knowledge, the reported capacitance value is superior in comparison to the previously reported CVD-based graphene supercapacitors [55][56][57][58][59]. The device exhibited good capacitance retention at high current densities (as shown in figure 6d) with respect to the specific capacitance at the current density of 0.05 mA cm -2 .…”

Spectroelectrochemistry of Electroactive Polymer Composite Materials

“…In situ Raman spectroelectrochemistry in a microdroplet setup was used to study the processes of preparation and redox cycling of two-dimensional graphene/polyaniline supercapacitors [ 136 ]. Selective formation of polyaniline on the graphene was confirmed.…”

Carbon Nanomaterials‐Enabled High‐Performance Supercapacitors: A Review

“…[ 149 ] The most commonly used carbon sources are CH 4 , C 2 H 2 , ethanol, etc., and the structure and types of graphene could be well tuned by changing the processing parameters like temperature, pressure, and precursors. Bláha et al [ 150 ] synthesized graphene by CVD method on a copper substrate, and then it was functionalized by phenylene sulfonic groups using a diazonium protocol; finally, PANI was polymerized on the surface of functionalized graphene to fabricate graphene/PANI composite electrode, which yielded an areal specific capacitance of 21.2 μF cm −2 at the scan rate of 500 mV s −1 , approximately ten times higher than that of pristine graphene (around 2.1 μF cm −2 ). Deyab et al [ 151 ] synthesized NiFe‐A@GNS nanocomposite material using NiFe 2 O 4 nanoparticles as a catalyst substrate and CH 4 as a carbon source through the CVD method and the preparation process is shown in Figure .…”