Electrochemically Deposited Pd鈥揚t and Pd鈥揂u Codeposits on Graphite Electrodes for Electrocatalytic H2O2 Reduction

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• 作者：Tharamani Chikka Nagaiah ; Dominik Sch盲fer ; Wolfgang Schuhmann ; Nina Dimcheva
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：August 20, 2013
• 年：2013
• 卷：85
• 期：16
• 页码：7897-7903
• 全文大小：370K
• 年卷期：v.85,no.16(August 20, 2013)
• ISSN：1520-6882

文摘

Improved electrocatalytic activity and selectivity for the reduction of H₂O₂ were obtained by electrodepositing Pd鈥揚t and Pd鈥揂u on spectrographic graphite from solutions containing salts of the two metals at varying ratio. The electrocatalytic activity of the resulting binary codeposits for H₂O₂ reduction was evaluated by means of the redox-competition mode of scanning electrochemical microscopy (SECM) and voltammetric methods. In a potential range from 0 to 鈭?00 mV (vs. Ag/AgCl/3 M KCl) at pH 7.0 in 0.1 M phosphate citrate buffer, the electrocatalytic activity of both Pd鈥揚t and Pd鈥揂u codeposits was substantially improved as compared with the identically deposited single metals suggesting an electrocatalytic synergy of the codeposits. Pd鈥揚t and Pd鈥揂u codeposits were characterized by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). Codepositing with Au caused a change of hedgehog-like shaped Pd nanoparticles into cauliflower-like nanoparticles with the particle size decreasing with increasing Au concentration. Codepositing Pd with Pt caused the formation of oblong structures with the size initially increasing with increasing Pt content. However, the particle size decreases with further increase in Pt concentration. The improved electrocatalytic capability for H₂O₂ reduction of the Pd鈥揚t electrodeposits on graphite was further demonstrated by immobilizing glucose oxidase as a basis for the development of an interference-free amperometric glucose biosensor.