Preparation of rough Pt modified Au electrode by silver staining and galvanic replacement reactions for amperometric and fuel-cell-based sensing of ethanol

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• 作者：Ling LiuAuthor Vitae ; Xiaoli QinAuthor Vitae ; Pei ZhangAuthor Vitae ; Aigui XuAuthor Vitae ; Mengzhen DaiAuthor Vitae ; Qingji Xie ; ^{xieqj@hunnu.edu.cn" class="auth_mail" title="E-mail the corresponding author}Author Vitae
• 关键词：Rough Pt on Au electrode ; Silver staining ; Galvanic replacement reaction ; Fuel cell ; Electrochemical ethanol sensing
• 刊名：Sensors & Actuators: B. Chemical
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：230
• 期：Complete
• 页码：77-86
• 全文大小：2523 K

文摘

This paper presents a new approach for preparing a rough Pt film on an electrodeposited Au modified Au disk electrode (Au_pla/Au) by silver staining and galvanic replacement reactions (GRRs), and the modified electrode is used for amperometric and fuel-cell-based sensing of ethanol. Briefly, Ag was stained on Au_pla/Au through chemical reduction of AgNO₃ by hydroquinone (Ag/Au_pla/Au). The GRRs between the stained silver and H₂PtCl₆ produced size-enlarged nanoparticles containing Pt and AgCl, and electroreduction and ammonia rinse of AgCl could efficiently enhance the porosity to finally obtain the Pt_GRRx/Au_pla/Au electrode, where x denotes the number of silver staining/GRR cycles. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, quartz crystal microbalance and cyclic voltammetry were used to characterize the modified electrode. The Pt_GRR4/Au_pla/Au electrode exhibited a linear anodic amperometric response to ethanol concentration from 0.01 mM to 11.3 mM with a limit of detection (LOD, S/N = 3) of 3 μM, excellent stability and acceptable selectivity, which was used for analysis of ethanol in real Chinese liquor samples with satisfactory results. An ethanol/O₂ fuel cell was constructed using two Pt_GRR4/Au_pla/Au electrodes, which showed a self-powered linear voltage response to ethanol concentration from 0.02 to 15.7 mM with a LOD of 15 μM.