Electrocatalytic oxidation of ascorbic acid on a lithium-doped tantalum oxide film coated electrode

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• 作者：Yanhong Zhao ; Congyan Li ; Wen Zhao ; Qiangqiang Du ; Bo Chi ; Jinjing Sun ; Zhanli Chai ; Xiaojing Wang
• 关键词：Tantalum oxide ; Ascorbic acid ; Electrocatalysis ; Density functional theory
• 刊名：Electrochimica Acta
• 出版年：2013
• 出版时间：30 September, 2013
• 年：2013
• 卷：107
• 期：Complete
• 页码：52-58
• 全文大小：3068 K

文摘

In this work, lithium-doped tantalum oxide (lithium-Ta₂O₅) particles were synthesized using a low-temperature hydrothermal method. X-ray photoelectron spectroscopy (XPS) indicated that the state of lithium on the Ta₂O₅ surface is the Li⁺ form. The crystal phase of the samples was analyzed using X-ray diffraction (XRD). The analysis revealed that the lithium-Ta₂O₅ particles are well crystallized into an orthorhombic phase. Calculation from density functional theory (DFT) indicated that the band gap of Ta₂O₅ narrows when it is doped with lithium, resulting in improved conductivity and electrocatalytic activity over Ta₂O₅. The electrocatalytic activity of a lithium-Ta₂O₅ film coated electrode was investigated in a 0.1 mol dm^?3 KCl solution containing ascorbic acid (AA) using cyclic voltammetry (CV). The lithium-Ta₂O₅ film coated electrode has excellent electrocatalytic activity toward the oxidation of AA with much reduced overpotential. The anodic peak potential of AA shifted from 0.72 V (versus Ag|AgCl) on a bare glassy carbon electrode (GCE) to 0.42 V on the lithium-Ta₂O₅ film coated electrode.