A comparative experimental and density functional study of glucose adsorption and electrooxidation on the Au-graphene and Pt-graphene electrodes

• Published in: International journal of hydrogen energy 2020-01, Vol.45 (1), p.490-500
• Main Authors: Caglar, Aykut, Düzenli, Derya, Onal, Isık, Tezsevin, Ilker, Sahin, Ozlem, Kivrak, Hilal
• Format: Article
• Language: English
• Subjects: Chemical vapour deposition; Density functional theory; Glucose electrooxidation; Graphene
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2019.10.163

At present, the graphene is covered on Cu foil with the 5 sccm hexane (C6H14) flow rate, 50 sccm hydrogen (H2) flow rate, and 20 min deposition time parameters by the CVD method. The graphene on the Cu foil is then covered onto few-layer ITO electrode. Furthermore, the Pt and Au metals are electrodeposited on graphene/ITO electrode with electrochemical method. These electrodes are characterized by Raman spectroscopy and Scanning Electron Microscopy-Energy Dispersive X-Ray analysis (SEM-EDX). The graphene structure is approved via Raman analysis. Au, Pt, and graphene network are openly visible from SEM results. In addition, glucose (C6H12O6) electrooxidation is investigated with cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) measurements. As a result, Pt-graphene/ITO indicates the best C6H12O6 electrooxidation activity with 9.21 mA cm−2 specific activity (highly above the values reported in the literature). In all electrochemical measurements, Pt-graphene/ITO exhibits best electrocatalytic activity, stability, and resistance compared to the other electrodes. The adsorption of the C6H12O6 molecule is examined theoretically over metal atom (gold and platinum)-doped graphene surfaces using the density functional theory (DFT) method. The interaction between C6H12O6 molecule and OH adsorbed Pt-doped surface is stronger than that of OH adsorbed Au-doped graphene surface thermodynamically according to the reaction energy values. [Display omitted] •Few layer graphene produced by the CVD method is succesfully coated on ITO.•Pt and Au are succesfully electrodeposited on few layer graphene/ITO electrode.•Pt-graphene/ITO indicates the best C6H12O6 electrochemical activity and stability.•C6H12O6 adsorption is examined via DFT over Au and Pt doped graphene surfaces.•The interaction between C6H12O6 and OH adsorbed Pt-doped surface is robust.