Electrothermal Annealing of Catalytic Platinum Microwire Electrodes: Towards Membrane-Free pH 7 Glucose Micro-Fuel Cells

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• 作者：James Weber ; Andrew J. Wain ; Gary A. Attard and Frank Marken
• 刊名：Electroanalysis
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：29
• 期：1
• 页码：38-44
• 全文大小：1796K
• ISSN：1521-4109

文摘

Surface activation and cleaning of platinum micro-wires of 25 micron diameter has been achieved by a short one-second electrothermal annealing treatment in air at 0.3 A (to orange glow). Voltammetric data suggest a decrease in the electrochemically active surface area with annealing time and a change in surface structure towards the Pt(100) crystalline face. The impact of electrothermal annealing on the electrocatalytic activity towards (i) oxygen reduction and (ii) glucose oxidation in pH 7 phosphate buffered aqueous solutions is investigated. In contrast to as-received platinum, annealed platinum produces an electrocatalytic response towards glucose oxidation with increasing glucose concentration. A short one-second anneal step is just as effective in enhancing catalysis as prolonged electrochemical cleaning in sulphuric acid. Finally, by combining a non-annealed and an annealed microwire electrode, a very simple membrane-free micro-fuel cell system is devised operating in phosphate buffer at pH 7 with linearly increasing power output reaching 2.2 nW cm⁻² for high glucose levels of 0.5 M.