Pt-Ni/MWCNTs复合催化剂的制备及电化学性能

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

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)对制备的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Pt-Ni/MWCNTs修饰电极进行电化学性能测试,结果表明,Pt-Ni/MWCNTs可直接催化葡萄糖氧化,对葡萄糖的灵敏度为571.68μA·mmol/(L·cm^2),线性范围1.0×10^(-5)~8.2×10^(-3)mol/L(R=0.999 4),检测限为0.5μmol/L(S/N=3)。此外,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。

A Pt-Ni / MWCNTs composite catalyst was successfully synthesized with platinum and nickel supported on multi-walled carbon nanotubes（ MWCNTs） by impregnation-reduction method. The structure of the as-prepared composite catalyst was characterized by transmission electron microscopy（ TEM） and X-ray diffractometer（ XRD）. The results show that Pt and Ni are uniformly loaded onto the carbon nanotubes. The Pt-Ni composite catalyst has an approximate particle size of 2 nm. XRD analysis demonstrates that the composite catalyst has a solid solution structure based on Pt crystal lattice. The electrochemical performance of the modified electrode by Pt-Ni / MWCNTs was evaluated by cyclic voltammetry and chronoamperometry in alkaline media. Electrochemical measurements indicate the Pt-Ni / MWCNTs catalyst can directly catalyze the oxidation of glucose and has a selectivity of571. 68 μA · mmol /（ L · cm^2） towards glucose oxidation. The prepared electrode displays a wide linear range from 10 μmol / L to 8. 2 mmol / L（ R = 0. 999 4） with the limit of detection of 0. 5 μmol / L（ S /N = 3）. Moreover,the electrode has an excellent electrocatalytic oxidation glucose,selectivity and repeatability. It can efficiently avoid the interferences from the oxidation of ascorbic acid,uric acid and dopamine.