Pt-Ni/MWCNTs复合催化剂的制备及电化学性能研究

Study on Preparation and Electrochemical Performance of Pt-Ni/MWCNTs Composite Catalysts

摘要:

采用溶液还原法将铂镍负载于多壁碳纳米管(MWCNTs)制备Pt-Ni/MWCNTs复合催化剂。利用透射电子显微镜(TEM)、 X射线衍射仪(XRD)对复合催化剂进行结构表征，结果表明，铂镍均匀负载到碳纳米管上，Pt-Ni粒子粒径约为2 nm。XRD分析结果表明，复合催化剂是以Pt晶格为基础的固溶体结构。采用循环伏安法和计时电流法在碱性条件下对修饰电极进行电化学性能研究，结果表明，Pt-Ni/MWCNTs可直接催化葡萄糖氧化，催化剂对葡萄糖的灵敏度为571.68 μA•mmol/(L•cm2)，线性范围1.0×10-5-8.2×10-3 mol/L (R=0.9994)，电极对葡萄糖的最低检测限为0.5 μmol/L(S/N=3)，该电极对葡萄糖有良好的电催化氧化性能，且选择性和重现性好，可有效避免抗坏血酸、尿酸和多巴胺的干扰。

Abstract:

Pt-Ni/MWCNTs composite catalyst was successfully synthesized with platinum and nickel supported on multi-walled carbon nanotubes (MWCNTs) by impregnation-reduction method. The Pt-Ni/MWCNTs catalyst was characterized by transmission electron microscopy (TEM) and X–ray powder diffraction (XRD). The results show that Pt and Ni were uniformly loaded onto the carbon nanotubes. The Pt-Ni composite catalyst has a approximate particle size of 2 nm. XRD demonstrate that the composite catalyst is a solid solution structure based on Pt crystal lattice. The electrochemical performance of the modified electrode was evaluated by cyclic voltammetry and chronoamperometry in alkaline media. Electrochemical measurements indicate Pt-Ni/MWCNTs could directly catalyze the oxidation of glucose and a selectivity of 571.68 μA•mmol/(L•cm2) towards glucose oxidation was obtained. The composite catalyst displayed a wide linear range from 10 μmol/L to 8.2 mmol/L (R=0.9994) with the limit of detection of 0.5 μmol/L (S/N=3). The sensor exhibits excellent selectivity, stability and repeatability. The interferences from the oxidation of ascorbic acid, uric acid and dopamine could be effectively avoided.