Electrocatalytic oxidation and detection of ethanol on an electroplated Pt/3D honeycomb-like nano-Au/Au disk electrode

The dynamic gas bubble template method was used to potentiostatically electrodeposit three-dimensional honeycomb-like porous nano gold (Au-H) at -3 V vs SCE on a gold disk electrode in an aqueous bath containing 50 mM HAuCl4 and 3 M NH4Cl (Au-H/Au). Then, Pt was potentiostatically deposited at -1 V vs SCE on the Au-H/Au electrode in 0.1 M aqueous KCI containing 4 mM H-2 PtCl6 to yield a Pt/Au-H/Au electrode. Scanning electron microscopy, X-ray diffraction pattern and cyclic voltammetry were employed to characterize the relevant electrodes. The Pt/Au-H/Au electrode of large specific surface area exhibits high electrocatalytic activity for ethanol oxidation in 0.5 M aqueous H2SO4 or 1 M aqueous KOH. The Pt/Au-H/Au electrode in 0.5 M aqueous H2SO4 shows a linear amperometric response to ethanol concentration from 0.05 mM to 43.3 mM with a sensitivity of 75.7 mu A cm(-2) mM(-1), a limit of detection (LOD, S/N = 3) of 2.3 mu M, and good selectivity, which is used to analyze ethanol in white-spirit/red-wine real samples with satisfactory results. (C) 2019 Elsevier B.V. All rights reserved.