基于聚吡咯纳米线的硝酸根离子传感器的研究

在碳酸钠和碳酸氢钠水溶液中,使用电化学非模板法制备得到聚吡咯(polypyrrole)纳米线修饰电极,然后在高氯酸锂溶液中浸泡24 h.在0.5 mol/L硫酸溶液中,采用固相微萃取电流法(EC-SPE)来检测水中的硝酸根离子,所用固相萃取氧化电位为0.85 V,时间300s,还原电位为-0.15 V,还原时间100s.考察了聚合电量、被测试液温度、酸度、共存离子对该修饰电极检测水样中的硝酸根离子浓度的影响.硝酸根离子的浓度与还原电流密度呈良好的线性关系,检测极限和灵敏度分别是2.43×10-5mol/L和65.99 mA/M cm2.

Study on Sensor of Nitrate Ions Based on Polypyrrole Nanowire Modified Electrode

The polypyrrole (PPy) nanowire modified electrode was prepared by electrochemistry of template-free method and then conditioned in 0.1M perchlorate acid for 24h. The electrochemical solid-phase microextraction(EC-SPE) and amperometric determination of nitrate with PPy nanowire modified electrode was conducted. The applied potential of EC-SPE was 0.85V for 300s and the electroreduction of nitrate was conducted in -0.15v for 100s in the solution of 0.5 M H2SO4. The polymerization charges, the pH of the test solution, the temperature of the solution and coexisting ions have significant effects on the corresponding reduction current density. The electrodes show a good linear response of reduction current density to nitrate ions concentration. The sensitivity and detection limit of the PPy nanowire modified electrode for nitrate are 65.99 mA/ M cm2 and 4.09×10-5 mol/L, respectively.