超薄金修饰的钯电极用于乙醇安培传感研究

Ultrathin Au Modified Pd Electrode for Amperometric Sensing of Ethanol

超薄贵金属膜具有独特的结构和功能,创新其制备方法,拓展其电化学应用具有重要意义。通过在镀Pd的玻碳电极(GCE)上电沉积欠导电Se超薄膜并作为模板,再与HAuCl4进行原电池置换反应,制备了超薄Au膜修饰的镀Pd电极(AuSe/Pd/GCE),并在碱性条件下采用循环伏安法研究了AuSe/Pd/GCE对乙醇的电催化氧化性能影响,并构建了乙醇安培传感器。研究表明,与裸Pd电极相比,AuSe/Pd/GCE对乙醇的电催化氧化活性更高;在最优条件下,修饰电极对乙醇的线性检测范围为0.025~10.000 mmol·L^-1,灵敏度为0.94(mA·cm^-2)/(mmol·L^-1),优于多数已报道的方法。此种以欠导电物质均匀电沉积薄膜为模板,采用原电池置换反应制备超薄贵金属膜的新方法有望在纳米电催化剂的制备及电催化与电分析研究中广泛应用。

Owing to the unique structure and functionality of ultrathin precious metal film,it is of great significance to innovate the preparation method and expand the electrochemical applications of ultrathin precious metal film.Herein,by using an ultrathin film of a less electron-conducting electrodeposited Se as the template and a subsequent galvanic replacement reaction(GRR)with HAuCl4,the ultrathin Au film modified Pd-electroplated glassy carbon electrode(AuSe/Pd/GCE)was fabricated.The electrocatalytic and electroanalytical performance of the modified electrode was studied.The electrocatalysis performance of the AuSe/Pd/GCE toward oxidation of ethanol was investigated in alkaline solution via cyclic voltammetry,and then the ethanol amperometric sensor was constructed.Compared with the bare Pd electrode,the AuSe/Pd/GCE showed the higher electrocatalytic active toward the electrocatalytic oxidation of ethanol.Under the optimal conditions,the AuSe/Pd/GCE showed a linear amperometric response to ethanol concentration from 0.025 mmol/L to 10.000 mmol/L with a sensitivity of 0.94(mA·cm-2)/(mmol·L-1),being superior to most of relevant reports.The new method for preparing the ultrathin precious metal film by GRR with the uniform electrodeposited ultrathin film of a less electron-conducting material presented here was expected to be widely used in the preparation of nano-electrocatalysts for their electrocatalysis and electroanalysis applications.