Synthesis of Graphene-like Films by Electrochemical Reduction of Polyhalogenated Aromatic Compounds and their Electrochemical Capacitor Applications


Kudas Z., GÜR E., EKİNCİ D.

LANGMUIR, vol.34, no.27, pp.7958-7970, 2018 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 34 Issue: 27
  • Publication Date: 2018
  • Doi Number: 10.1021/acs.langmuir.8b01177
  • Journal Name: LANGMUIR
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.7958-7970
  • Eskisehir Osmangazi University Affiliated: No

Abstract

Graphene is a promising two-dimensional nanomaterial for many applications due to its exciting properties. In the past decade, a variety of techniqueseach with its own set of advantages and disadvantageshave been developed to prepare graphene, and there are ongoing efforts to improve these techniques and to reveal new approaches. Here, we describe a simple and low-cost process for the bottom-up synthesis of graphene-like films. This new methodology involves a two-step procedure. (i) formation of polyaromatic ring structures by the repeated covalent coupling of aryl radicals generated from electrochemical reduction of polyhalogenated aromatic compounds in aprotic solvent, and (ii) production of carbon networks by heating of polyaromatic surface films. Accordingly, polymeric films were prepared on the electrodes by electrochemical reduction of polyhalogenated compounds such as hexafluorobenzene (HFB), hexachlorobenzene (HCB), and hexabromobenzene (HBB), and then polymer films were annealed at 400 degrees C for 30 min. The structure and surface characteristics of electrodeposited carbon films under self- and thermal-annealing conditions were studied by spectroscopic and morphological techniques. Also, the capacitance performance of the films was evaluated by means of cyclic voltammetry, galvanostatic chargedischarge, and electrochemical impedance spectroscopy. Results indicate that graphene-like carbon films can be achieved by use of the electrochemical approach under mild conditions without expensive equipment, and also that these carbon materials are very promising for low-cost energy-storage devices.