铅在氧化石墨烯-纳米氧化镍修饰玻碳电极上的电化学行为

Electrochemical Behaviour of Lead on Graphene Oxide-nano Nickel Oxide Modified Glassy Carbon Electrode

用氧化石墨烯-氧化镍纳米复合膜修饰玻碳电极,制备了电化学传感器.用循环伏安法研究了铅在该电极上的电化学行为,建立了差分脉冲溶出伏安法测定痕量铅的电化学分析法,详细优化了氧化石墨烯的用量、富集电位、富集时间、电聚圈数、底液的pH值等测定条件.研究结果表明:在优化条件下,Pb2+的浓度在1×10-7～1×10-6mol/L的范围内与溶出峰电流呈良好的线性关系,检出限为1×10-8mol/L.将该方法用于水样中Pb2+的测定,回收率为96.5%～104.2%.

Graphene oxide was coated on glassy carbon electrode and nickel oxide was then electrodeposited on the modified electrode to fabricated electrochemical sensor.The electrochemical behaviors of lead on the modified electrode were investigated by cyclic voltammetry.A novel differential pulse stripping voltammetry was developed for the detection of lead based on the modified electrode.The experimental parameters such as the pH of supporting electrolyte,the amount of graphene oxide suspension,the accumulation potential and time,were optimized in detail.The results showed that the peak currents varied linearly with the concentration of Pb^（2＋） over the range from 1×10^（-7） to 1×10^（-6） mol/L with the detection limit of 1×10^（-8） mol/L.The proposed method was used to determine Pb^（2＋） in water samples with the average recoveries were 96.5%~104.2%.