Electrochemical characterization of electrochemically reduced graphene coatings on platinum. Electrochemical study of dye adsorption. (1st June 2015)

• Record Type: Journal Article
• Authors: Molina, J.; Fernández, J.; García, C.; del Río, A.I.; Bonastre, J.; Cases, F.
• Is Part Of: Electrochimica acta. Volume 166(2015)
• Page Start: 54
• Page End: 63
• Publication Date: 2015-06-01
• Subjects: graphene -- reduced graphene oxide -- scanning electrochemical microscopy -- dye -- adsorption; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2015.03.054
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: Pt electrodes coated with reduced graphene oxide (RGO) were obtained by CV. CV and EIS showed the increase in capacitance due to RGO deposition. Redox mediator influences the electrochemical response observed by SECM. CV was used to monitor and induce dye adsorption on Pt/RGO electrodes. Electrochemical adsorption increased dye adsorption compared to ocp adsorption. Abstract: Reduced graphene oxide coatings were synthesized by cyclic voltammetry on Pt electrodes. Electrochemically reduced graphene oxide was analyzed by scanning electrochemical microscopy for the first time. The redox mediator influences the electrochemical response; thus Ru(NH3 )6 3+ and Fe(CN)6 3− gave a similar response and Fe 3+ gave the poorest response. Pt electrodes coated with reduced graphene oxide were also used in the electrochemical adsorption (performed by cyclic voltammetry) of different dyes (Methylene Blue, Procion MX-2R and Amaranth). Electrochemical methods proved to be useful to monitor the adsorption of dyes on the surface of graphene materials. After adsorption, with Methylene Blue and Procion MX-2R, the appearance of a stable redox pair (with 1 electron transfer) was observed. This redox pair was adsorption controlled since the intensity of the redox pair was proportional to the scan rate used. Electrochemical adsorption multiplied by 3 the electrical charge of the Methylene Blue adsorbed on the surface of reduced graphene oxide when compared with simple adsorption at open circuit potential. In the case of Procion MX-2R, the increase obtained was even higher, with a 6-fold increase.