全固态硝酸根离子选择性电极的制备及其性能研究

Preparation and properties of all-solid-state nitrate ion selective electrode

硝酸盐含量常用于判断水体质量和受污染程度,是重要的水质检测指标。以玻碳电极为基底电极、聚3,4-乙烯二氧噻吩(PEDOT)为固态接触层、聚氯乙烯(PVC)为敏感基膜制备了一种新型全固态硝酸根离子选择性电极,并考察了该电极的电化学特性。结果表明,以PEDOT为固态接触层能有效促进电极离子—电子之间信号传导,提高电极的稳定性。该电极在1×10^(-1)~1×10^(-5)mol/L范围内的硝酸铵溶液中呈良好的能斯特响应,响应斜率可达53.7 m V/dec,响应时间在50 s以内。该电极的重现性、选择性好,使用寿命超过3个月。

The content of nitrates can often be used to judge the quality of water bodies and the degree of pollution,and it is an important water quality testing index.A novel all-solid-state nitrate ion selective electrode is prepared by using glassy carbon electrode as the base electrode,poly(3,4-ethylenedioxythiophene)(PEDOT)as solid contact layer,and polyvinyl chloride(PVC)as the sensitive base membrane.The electrochemical characteristics of the electrode are investigated.It is found that using PEDOT as solid contact layer can effectively promote the ion-electron signal conduction between the electrodes and improve the stability of the electrodes.Besides,the electrode exhibits a good Nernst response in ammonium nitrate solution with a concentration in the range of 1×10^(-1)-1×10^(-5) mol·L^(-1),the response slope can reach53.7 m V·dec^(-1),and the response time is within 50 s.It shows a good reproducibility,a high selectivity,and a service life exceeding 3 months.