钛酸盐纳米管修饰玻碳电极对水体中Pb(Ⅱ)的电化学检测

Electrochemical determination of Pb(Ⅱ)in water using titanate nanotubes modified glassy carbon electrode

为实现淡水中微量Pb(Ⅱ)的快速检测,通过水热法制备了一种钛酸盐纳米管(TNTs)电化学传感器,在Pb(Ⅱ)浓度为0.1~6μmol·L^(-1)的范围内呈现良好的线性关系,其电流敏感度和检测限分别为49.87μA·(μmol·L^(-1))^(-1)和0.08 nmol·L^(-1),明显优于原材料TiO2.从电解质pH、沉积电压、沉积时间3个方面优化了检测条件.循环伏安法和交流阻抗法的结果显示,TNTs修饰的玻碳电极具有良好的导电性能.X射线衍射、红外光谱和X射线光电子能谱技术分析表明,TNTs优良的电化学性能归结于其表面丰富的可交换Na+和层间丰富的羟基基团.最后,探究了TNTs修饰电极在常见离子共存时的抗干扰情况,并将其应用于实际水源的检测,检测结果具有良好的重现性、稳定性和抗干扰性.

The Titanate Nanotubes(TNTs)electrochemical sensor synthesized by hydrothermal method was used for the electrochemical detection of Pb(II)in freshwater.The TNTs modified glassy carbon electrode showed a good linear range of Pb(Ⅱ)detection from 0.1 to 6μmol·L^(-1),and exhibited a high detection sensitivity of 49.87μA·(μmol·L^(-1))^(-1) under the optima detection conditions,significantly better than the raw material TiO_(2).The cyclic voltammetry and AC impedance results suggested that the TNTs modified electrode has good conductivity.The analysis of X-ray diffraction(XRD),infrared spectroscopy(IR),and X-ray photoelectron spectroscopy(XPS)showed that the excellent electrochemical properties of TNTs were attributed to the abundant exchangeable Na+on the surface and the productive hydroxyl groups between the layers.Finally,the TNTs modified electrode was utilized in actual water samples to investigate the interference resistance of the common ions.The TNTs modified electrode was validated for detecting Pb(Ⅱ)in several real water samples,which showed distinguished selectivity and robustness.