title: Direct electro-deposition of graphene from aqueous suspensions.
abstract: We describe the direct electro-chemical reduction of graphene oxide to graphene from aqueous suspension by applying reduction voltages exceeding -1.0 to -1.2 V. The conductivity of the deposition medium is of crucial importance and only values between 4-25 mS cm(-1) result in deposition. Above 25 mS cm(-1) the suspension de-stabilises while conductivities below 4 mS cm(-1) do not show a measurable deposition rate. Furthermore, we show that deposition can be carried out over a wide pH region ranging from 1.5 to 12.5. The electro-deposition process is characterised in terms of electro-chemical methods including cyclic voltammetry, quartz crystal microbalance, impedance spectroscopy, constant amperometry and potentiometric titrations, while the deposits are analysed via Raman spectroscopy, infra-red spectroscopy, X-ray photoelectron spectroscopy and X-ray diffractometry. The determined oxygen contents are similar to those of chemically reduced graphene oxide, and the conductivity of the deposits was found to be ∼20 S cm(-1).
authors.affiliation: Monash University, School of Chemistry, Clayton, Victoria, 3800, Australia. Matthias.hilder@monash.edu
authors.forename: Matthias
authors.initials: M
authors.lastname: Hilder
authors.forename: Bjorn
authors.initials: B
authors.lastname: Winther-Jensen
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Maria
authors.initials: M
authors.lastname: Forsyth
authors.forename: Douglas R
authors.initials: DR
authors.lastname: MacFarlane