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

• DOI: 10.1021/acsami.1c05054
• Publication Date: 2021-07-16T23:41:01Z
• Authors: Michal Bláha; Milan Bouša; Václav Valeš; Otakar Frank; Martin Kalbáč
• Keywords: areal capacitance; Chemical Sciences not elsewhere classified; Physiology; Information Systems not elsewhere classified; Marine Biology; graphene electrochemical doping; 02 engineering and technology; walled carbon nanotubes; Electrochemical Operation Nanocompo.; Synthesis Strategy; two-dimensional heterostructure; reaction conditions; force microscopy; Sociology; graphene materials; monolayer; Raman spectroelectrochemistry; oxidative polymerization; conducting polymer; composite; aniline; supercapacitor; CVD-graphene; Evolutionary Biology; bulk polyaniline; polyaniline-graphene nanocomposites; electrochemical operation; 660; microdroplet setup; Cell Biology; 2400 cycles; 200 cycles; polyaniline redox transitions; polyaniline monolayer; cyclic voltammetry; electrodes; interfacial polymerization; Raman spectroscopy; raman-spectroscopy; Medicine; ammonium persulfate; phenylene sulfonic groups; 0210 nano-technology; Physical Sciences not elsewhere classified; Scanning electron microscopy; high-performance supercapacitors

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.