纳米多级孔Pd-HSiO1.5/Ni-Co合金复合电极的构建及电催化特性研究

Ni-Co alloy electrode as a novel electrode has the advantages of high electrocatalytic activity and excellently electrochemical response. Ni-Co alloy electrode is used for preparing electrochemical sensor because of its excellent performance and has attracted considerable attention in recent years. At present, the electrochemical sensors of detecting antibiotics have the disadvantages of high cost, low sensitivity and difficult to discriminate the different antibiotics. In order to improve sensitivity and decrease the cost for detecting antibiotics, this project is aim at the fabrication of a nanoporous electrochemical sensor base on the nano hierarchically porous Pd-HSiO1.5/Ni-Co alloy composite electrode. With this purpose, we propose the fabrication of nano hierarchically porous Pd-HSiO1.5/Ni-Co alloy composite electrode using the method of composite electrodeposition by using nano hierarchically porous Pd-HSiO1.5 particles as the composite particles, the nano hierarchically porous HSiO1.5 particles are prepared by the method of template, and after loading Pd, which recults in the composite electrode with high surface area, high electrocatalytic activity and low cost. In order to discriminate the different antibiotics and detect antibiotics with high sensitivity, the typical characteristics of electrocatalysis of the different antibiotics on the composite electrode are studied by the methods of direct electrochemical analysis and indirect electrochemical analysis. The project will reveal the typical characteristics of electrocatalysis and electrochemical behaviors of the different antibiotics such as Alcohols, esters, amines, sugar and ketones by obtaining their respective electrochemical response signals. Finally realize the recognition of different kinds of antibiotics and high sensitive rapid quantitative detection.

Ni-Co合金电极作为一种新型电极，其主要的特性在于具有较高的电催化活性及特殊的电化学响应，利用这一特性将其作为电极材料用于制备电化学传感器是电化学领域研究的新热点。本项目针对目前检测抗生素存在操作繁琐，成本高，灵敏度不高，难以识别不同种类抗生素等缺点，提出采用模板法制备空心的纳米多级孔硅氢化合物颗粒，并负载上钯，获得大比表面的纳米多级孔Pd-HSiO1.5复合粒子，采用复合电沉积的方法，制备出纳米多级孔Pd-HSiO1.5/Ni-Co合金复合电极，构建出一种新型纳米多级孔合金复合电极电化学传感器。通过直接和间接电化学分析法，并结合多种电化学研究技术，对醇类、酯类、胺类、糖类以及酮类等主要种类抗生素在复合电极上的电催化特性进行分析，揭示不同种类抗生素的电催化氧化机理和行为，获取不同种类抗生素电催化的特征电化学信号，最终实现对不同种类抗生素的识别和高灵敏快速定量检测。

Ni-Co合金对许多醇类、酚类、醛类和多羟基类等有机化合物都有较高的电催化活性，但多数都是对伯醇催化氧化的研究，而对多羟基类抗生素的研究较少，其主要的原因是电化学检测方法不能广泛地满足高灵敏度和快速检测的需求。本项目在柠檬酸体系中，采用单因素正交试验方法进行了Ni-Co合金电极单脉冲电沉积试验和优化，研究镀液中主要组分和工艺条件(镀液中CoSO4.7H2O的浓度、阴极平均电流密度、占空比和镀液温度等) 对Ni-Co合金电极的组分和表面形貌的影响，得出电沉积Ni-Co合金电极的最佳镀液配方和工艺参数。在此基础上，探讨了不同电沉积时间和不同组分的Ni-Co合金电极对电极电催化性能的影响。结果表明：当镀液中CoSO4∙7H2O的浓度为3 g∙L-1，阴极平均电流密度为2.5 A∙dm-2，单脉冲电源占空比为10 %，电沉积时间为25 min和电极中Ni:Co ≈ 57:43时，Ni-Co合金电极的对土霉素的电催化性能最好。以非离子型表面活性剂P123为介孔模板剂和阳离子氟碳表面活性剂FC-04为抑制剂形成有机模板胶束，三乙氧基硅烷(TES)为硅源，在酸性条件下成功制备出直径大约为70 nm硅氢化合物纳米颗粒，利用硅氢键的还原性，进一步制备出负载Pd的纳米多级孔硅氢化合物(Pd-HSiO1.5)。在电沉积Ni-Co合金电极的基础上，在镀液中添加纳米多级孔Pd-HSiO1.5颗粒，制备出纳米多级孔Pd-HSiO1.5/Ni-Co复合电极。将制备的纳米多级孔Pd-HSiO1.5/Ni-Co复合电极运用于四环素类抗生素的检测，结果表明：纳米多级孔Pd-HSiO1.5/Ni-Co复合电极能够有效地检测土霉素、强力霉素及四环素其各自的线性方程为Ip(mA) =9.14+10.15C (mM)、Ip(mA) =10.23+8.87C (mM)和Ip(mA) =10.22+9.13C (mM)。最后对纳米多级孔Pd-HSiO1.5/Ni-Co复合电极的重现性、精确性及抗干扰性进行探讨，结果表明电极具有较好的重现性及精确性，氨苄青霉素钠和利福平等其他抗生素对纳米多级孔Pd-HSiO1.5/Ni-Co复合电极检测土霉素的干扰性较小。