Abstract

This work reports the synthesis and characterization of titanate nanotubes (TiNTs) and their use for the construction of an electrochemical sensor for lead (II) determination in water samples. TiNTs were prepared from TiO₂ by a hydrothermal route at 150 °C for 24 h in alkaline conditions. X-ray diffraction (XRD) measurements show peak enlargement and the presence of trititanate with different spaces between layers confirming the production of TiNTs of nanometric dimensions. In addition, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images demonstrated the presence of dispersed, homogenous, and nanometric tubular structure. TiNTs were used for the modification of carbon paste electrodes and evaluated for determination of lead (II) by differential pulse adsorptive stripping voltammetry (DPAdSV). Using the optimized conditions, the developed method provided a linear dynamic range (LDR) from 0.77 to 7.71 µM and limits of detection and quantification of 0.23 and 0.77 µM, respectively. Studies of addition and recovery in spiked water sample were performed, obtaining a recovery of 104.6%. A repeatability study resulted in a relative standard deviation of 11% for consecutive measurements. Using the same electrode, a reproducibility study provided a relative standard deviation of 3.9%.

摘要

这项工作报告了钛酸盐纳米管 (TiNT) 的合成和表征及其在构建用于测定水样中铅 (II) 的电化学传感器中的用途。TiNTs 由 TiO _2制备通过在碱性条件下在 150 °C 下 24 h 的水热路线。X 射线衍射 (XRD) 测量显示峰扩大和三钛酸盐的存在，层与层之间的空间不同，证实了纳米尺寸的 TiNT 的产生。此外，扫描电子显微镜 (SEM) 和透射电子显微镜 (TEM) 图像表明存在分散、均匀和纳米管状结构。TiNT 用于碳糊电极的改性，并通过差分脉冲吸附溶出伏安法 (DPAdSV) 评估铅 (II) 的测定。使用优化的条件，开发的方法提供了从 0.77 到 7.71 µM 的线性动态范围 (LDR)，以及分别为 0.23 和 0.77 µM 的检测限和定量限。对加标水样的添加和回收率进行了研究，回收率为 104.6%。重复性研究导致连续测量的相对标准偏差为 11%。使用相同的电极，重复性研究提供了 3.9% 的相对标准偏差。