Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6607804 | Electrochimica Acta | 2016 | 34 Pages |
Abstract
We report the synthesis of graphene via the electrochemical reduction of graphene oxide (GO). In this study, GO nanosheets from aqueous dispersion were pre-assembled on a glassy carbon (GC) electrode and then electrochemically reduced in 1Â M KOH under various constant reduction potentials in the range of â0.6Â V to â1.5Â V (vs. Ag/AgCl). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy analyses revealed that the graphitic structure was substantially restored in the resulting electrochemically reduced graphene oxide (ERGO). The ERGO electrodes exhibited significantly enhanced catalytic activity toward the oxygen reduction reaction (ORR) in an alkaline medium compared with the initial GO electrode. Of the ERGO electrodes produced at various cathodic potentials, the ERGO-1.2Â V electrode, which was produced at a reduction potential of â1.2Â V, demonstrated the best catalytic activity toward the ORR in an alkaline medium. The ORR on GO and ERGO electrodes was shown to proceed via a two-electron mechanism at low overpotentials. The agreement between the spectroscopy results and electrochemical measurements provide strong evidence that the enhanced ORR catalytic activity is mainly attributed to the restoration of GO's graphitic structure. Furthermore, the ERGO-1.2Â V electrode showed excellent tolerance to the methanol poisoning effect compared with a Pt/C catalyst electrode.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Shaw Yong Toh, Kee Shyuan Loh, Siti Kartom Kamarudin, Wan Ramli Wan Daud,