Ultrasonic Electrodeposition of Gold−Platinum Alloy Nanoparticles on Ionic Liquid−Chitosan Composite Film and Their Application in Fabricating Nonenzyme Hydrogen Peroxide Sensors

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• 作者：Fei Xiao ; Faqiong Zhao ; Yafen Zhang ; Gaiping Guo ; Baizhao Zeng
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：January 22, 2009
• 年：2009
• 卷：113
• 期：3
• 页码：849-855
• 全文大小：268K
• 年卷期：v.113,no.3(January 22, 2009)
• ISSN：1932-7455

文摘

Gold−platinum nanoparticles (AuPt NPs) were fabricated on chitosan (Ch)−ionic liquid (i.e., trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide, [P(C₆)₃C₁₄][Tf₂N]) film by using an ultrasonic electrodeposition method for the first time. Ch acted as an adsorbent for the metal ions, and [P(C₆)₃C₁₄][Tf₂N] played a dual role of matrix and stabilizer in the formation of the nanoparticles. The obtained AuPt NPs were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. It was found that they were well-dispersed on the composite surface, and their diameters were 10−20 nm. Furthermore, they exhibited the features of an alloy, and the atomic ratio of Au/Pt in the alloy NPs was close to the concentration ratio of AuCl₄⁻/PtCl₆²⁻ in the solution. Electrochemical observation showed that the AuPt−Ch−[P(C₆)₃C₁₄][Tf₂N] modified glassy carbon electrode (GCE) had a large electroactive surface area and small electron transfer resistance. When the ratio of AuCl₄⁻/PtCl₆²⁻ was around 3:1, the resulting electrode (i.e., Au₃Pt₁−Ch−[P(C₆)₃C₁₄][Tf₂N]/GCE) displayed high catalytic activity to the reduction of hydrogen peroxide (H₂O₂). Chronoamperometric experiments showed that at an applied potential of 0.05 V (vs SCE), the reduction current of H₂O₂ was linear to its concentration in the range of 5−355 nM, and the detection limit was found to be 0.3 nM on the basis of the signal-to-noise ratio of 3. The as-prepared nonenzyme hydrogen peroxide sensor exhibited excellent stability, repeatability, and selectivity.