Electrochimica Acta, Vol.188, 111-119, 2016
Complete Coating of Underlying Pt Electrodes by Electrochemical Reduction of Graphene Oxide
Graphene oxide electrochemically reduced from aqueous and nonaqueous graphene oxide suspensions was compared. The protocol that utilized the nonaqueous suspension resulted in a more reproducibly complete covering of the underlying Pt electrode while still retaining its electrochemical integrity. The hydrogen evolution reaction was found to be detrimental to achieving complete electrode coverage from the aqueous suspension due to H-2 bubbles physically dislodging previously reduced graphene oxide. However, since this parasitic reaction does not proceed as readily in organic solvents such as DMF, the nonaqueous reduction was able to form a complete layer once the aqueous suspension was drop-carted and dried on the Pt electrode. The graphene oxide-coated electrodes resulting from both aqueous and nonaqueous protocols were compared using electrochemistry, SEM, AFM, and XPS. Overall, the sample produced from the nonaqueous suspension possessed a significantly rougher morphology and was determined to possess a higher amount of reduced carbon than that produced using the aqueous suspension. (C) 2015 Elsevier Ltd. All rights reserved.