AFM and Cu Electrodeposition Studies of Reduced Graphene Oxide Modified Au(111) Facets Prepared using Electrodeposition and Post-Deposition Pulse Treatment

Abstract

The structural and electrochemical characteristics of electrodeposited graphene oxide (GO) onto a single crystal gold bead electrode was studied using AFM and Cu electrodeposition. Optimal deposition uniformity was realized by rotation of the electrode, suggesting an initial electrophoretic deposition occurs followed by some reduction of the GO. Potential pulse treatments to reducing potentials for a short time significantly improve the electrochemical characteristics of the electrochemical reduced graphene oxide (ERGO). Both under-potential and over-potential Cu electrodeposition was used to characterize the quality of the ERGO deposit and showed that the gold surface was completely coated with ERGO only after potential pulsing treatments. AFM analysis of ERGO modified Au(111) facet on the gold bead electrode revealed the deposition was composed of sheets of GO/ERGO as well as much rougher deposits. AFM showed that the potential pulsing treatment resulted in the nucleation and growth of electrodeposited Cu nanoparticles over much of the ERGO surface, in contrast to the limited deposition of nanoparticles on the untreated GO deposit. The ERGO modified gold surface prepared using electrodeposition followed by potential pulse treatments results in conductive and electrochemically active ERGO surfaces.

Development of a Graphene-Oxide-Deposited Carbon Electrode for the Rapid and Low-Level Detection of Fentanyl and Derivatives

“…This would act to remove the non-conductive overlayer and allow for ingress of the electrolyte into the newly uncovered or newly created porous structures. 23 , 24 The EIS results are in line with this hypothesis.…”

“…The electrophoretically deposited layers of GO were electrochemically reduced onto the GC electrode during deposition at −0.85 V, but as detailed previously, , reductive potential pulses were observed to improve the quality of the deposit. The modified electrode was placed into the PBS electrolyte (without or with fentanyl) and a series of potential pulses were applied (−1.8 V for 0.1 s, 0 V for 1 s, typically repeated 200 times), while the solution was stirred.…”

“… 21 To improve the analytical performance, the GC surface was modified with the electrophoretic deposition and reduction of GO following the procedures developed previously on a gold electrode. 23 , 24 …”

“…Pulsing was previously reported to remove the GO overlayer that was deposited electrophoretically but not reduced. 23,24 This overlayer on the pre-pulse ERGO deposit appeared to have similar EIS characteristics (the same CPE exponent independent of the deposition time/charge) except for the increased roughness with longer deposition time (Figure S5). The negative potential pulse treatment was proposed to reduce water and create H 2 on the electrically conductive ERGO.…”

“…21 To improve the analytical performance, the GC surface was modified with the electrophoretic deposition and reduction of GO following the procedures developed previously on a gold electrode. 23,24 Characterization of the Electrophoretic Deposition of GO Films on GC. Following previously developed methods, GO was electrophoretically deposited and reduced on the GC electrode, producing an electrochemically reduced GO (ERGO) film.…”