【作者】 熊长宏；

【导师】 李念兵；

【作者基本信息】 西南大学 ， 物理化学， 2011， 硕士

【摘要】 自从2000年Wang等把铋膜电极运用于电化学溶出伏安分析研究领域后,由于其具有低毒性,制备简便和与汞膜电极相似的电化学性质,该类电极的运用和研究引起许多电分析化学工作者的广泛关注,已成为可代替汞膜电极的新型电极。此外,在聚合物膜基底上构建铋膜电极可提高方法的灵敏度和选择性。锡和铋在化学元素周期表中处于对角线位置,因此具有与铋相似的化学性质且锡是更绿色环保的金属,开展新型环境友好锡膜电极的制备及其应用研究具有重要的意义。本文研究了不同基底材料上铋膜和锡膜电极的制备方法及其在重金属离子检测中的应用。主要研究内容如下：1.聚对氨基苯磺酸修饰的锡铋复合膜电极的制备及其对镉离子的测定以聚对氨基苯磺酸膜为基底采用同位镀膜技术,制备了聚对氨基苯磺酸／锡-铋复合膜电极。并研究了镉离子在该电极上的阳极溶出伏安行为,优化了待测液的pH,铋与锡的浓度比例,沉积时间和沉积电位等实验条件,与铋膜电极相比,这种聚对氨基苯磺酸修饰的锡铋复合膜电极具有更好的电极响应,而且该电极具有更好的稳定性和更低的毒性,在最佳实验条件下,镉的氧化峰与其浓度在0.5到55.0μg L-1范围内呈良好的线性关系,检出限为0.32μgL-1。该电极用于自来水中镉离子的测定,结果令人满意。2.聚苯胺修饰的铋膜电极的制备及其对钻离子的测定在聚苯胺膜修饰的玻碳电极上预镀一层铋膜得到新型的聚苯胺／铋膜电极,并采用方波吸附溶出伏安法在pH=8.0的氨水缓冲溶液中实现了钴离子的测定。聚苯胺膜通过增加表面吸附Co-DMG复合物位点,提高了钴在电极上的电化学响应。对比单纯的铋膜电极,聚苯胺修饰的铋膜电极表现出更为灵敏的性质。实验还优化了DMG的浓度,待测溶液的pH,吸附电位和吸附时间等实验参数。在最佳实验条件下,钴的还原峰电流与其浓度有良好的线性关系,线性范围是1.0-120.0μg L-1,检出限为0.84μg L-1。将该新型电极应用于江水中的钴离子的测定也得到了比较好的结果。3.掺杂蒙脱土钠的铋膜碳糊电极的研究及其对铅离子的测定在碳糊电极中掺杂一定量的蒙脱土钠制得掺杂蒙脱土钠的碳糊电极,并采用同位镀铋的方法研究了铅离子在该电极上的响应。与裸的碳糊电极、铋膜碳糊电极和蒙脱土钠掺杂的碳糊电极相比,这种新电极显示了优越的性质和更高的灵敏度。说明蒙脱土钠对金属离子有一定的吸附作用。接着优化了影响铅响应的实验参数包括碳糊中碳粉和蒙脱土钠的比例,待测溶液的pH,铋的浓度,沉积电位和沉积时间。结合方波阳极溶出伏安,铅离子在浓度范围0.3到85.0μg L-1与溶出电流具有很好的线性关系,检出限为0.28μg L-1。这种铋膜/蒙脱土钠碳糊电极对自来水和江水中铅离子也具有很好的电化学响应。4.锡膜碳糊电极的研究及其对铜离子的测定在碳糊电极表面采用同位镀锡的方法制备了锡膜碳糊电极,研究了该电极在pH=3.6的醋酸溶液中对铜离子的方波阳极溶出伏安响应。锡膜的存在增加了铜在碳糊电极表面的富集,从而提高了铜的响应。与裸碳糊电极相比,锡膜碳糊电极对于铜的测定具有更高的灵敏度。而且利用锡膜电极测定铜避免了用铋膜电极测定铜时溶出峰部分重叠的缺点。后续实验优化了锡的浓度,溶液的pH,沉积电位和沉积时间等实验条件。在最优条件下,铜的氧化峰电流与浓度在1.0-75.0μg L-1范围内具有线性关系,检出限为0.5μgL-1。这种新型的电极也成功用于河水中铜离子的检测。更多还原

【Abstract】 Since Wang et al introduced the bismuth film electrodes (BiFEs) in electrochemical stripping voltammetry analysis in 2000, these new electrodes have been attracted the attention of many electroanalytical researchers because of their remarkable characteristics of small toxicity, simple preparation and good electrochemical properties, and the traditional mercury electrode in electroanalytical chemistry fast replaced by bismuth film electrode. Furthermore, the sensitivity and selectivity of the BiFFs could be further improved by depositing on the polymeric membrane. Moreover, stannum and bismuth are in catercorner position at periodic table of chemical elements, so the electrochemical characteristics of stannum is similar to that of bismuth. In addition, stannum is a more "green" element, with very low toxicity and cost, so it is important to investigate the preparation and application of a novel environmentally friendly stannum film electrode. This paper continued to investigate the application and preparation of bismuth film and stannum film electrode for analysis of metal ions on a series of substrates materials. The main research contents are as follows:1. Fabrication of stannum/bismuth/poly(p-aminobenzene sulfonic acid) film electrode and its application for measurement of cadmium (Ⅱ)A new method for a trace analysis of metal cadmium ion has been developed on the stannum/bismuth/poly(p-aminobenzene sulfonic acid) film electrode. This new electrode was prepared by in situ depositing stannum, bismuth and target metal on the poly(p-aminobenzene sulfonic acid)(p-ABSA) coated glassy carbon electrode. Some key factors including the pH of measure solution, the proper proportion between Bi(Ⅲ) and Sn(Ⅱ), the deposition time and the deposition potential have been studied and optimized. Compared with the traditional bismuth film electrode, the stannum/bismuth/poly(p-ABSA) film electrode displayed higher stripping current response. In addition, it has the advantages of better stability and less toxicity. Under the optimum conditions, the linear calibration graph for Cd(II) in the concentration range of 0.5 to 55.0μg L-1 was obtained and the detection limit was 0.32μg L-1. The method was applied to the analysis of cadmium ion in tap water sample with satisfactory results.2. Fabrication of bismuth/poly(aniline) film modified electrode and its application for measurement of cobalt (Ⅱ)A sensitive method was developed for the determination of Co(II) by square wave adsorpting stripping voltammetric using bismuth coated poly(aniline) modified film electrode (Bi/poly(aniline)FE) in ammonia buffer solution (pH 8.0). The electrochemical response of cobalt was apparently improved by poly(aniline) due to the enhanced the surface absorption sites of Co-DMG complexs. In comparison with the bismuth film electrode, the Bi/poly(aniline)FE proved to be more sensitive, experimental parameters including the concentrations of DMG, pH of measure solution, adsorption potential and adsorption time were investigated and optimized. Under optimized conditions, the peak current was proportional to the concentration of Co(II) in the range of 1.0-120.0μg L-1 with the detection limit of 0.84μg L-1. Application of the new electrode for the determination of cobalt in river water samples gave good results.3. Study on the bismuth film modified doped sodium montmorillonite carbon paste electrode and its application for measurement of lead (Ⅱ)A simple and reliable electrochemical method for the determination of lead using a bismuth film modified doped sodium montmorillonite carbon paste electrode (Bi/Na-MM/CPE) was described. The new electrode significantly enhanced the sensitivity of determination for Pb(II) and exhibited superior performance in comparison with the bare carbon paste electrode (CPE), bismuth film modified carbon paste electrode (Bi/CPE), and Na-MM modified carbon paste electrode (Na-MM/CPE). Many parameters such as the composition of the paste, pH of measure solution, the Bi(Ⅲ) concentration, deposition time and deposition potential that influenced the response of lead were investigated. Combination with square-wave anodic stripping voltammetry, the new electrode displayed excellent linear behavior in the examined concentration range from 0.3 to 85.0μg L-1 Pb(Ⅱ) (r=0.996) with detection limit of 0.28μg L-1. The electroanalytical performance of Bi/Na-MM/CPE for lead was successfully tested in tap water and river water samples.4. Study on the stannum film modified carbon paste electrode and its application for measurement of copper (Ⅱ) A selective and sensitive method was developed for the determination of Cu(Ⅱ) by square wave anodic stripping voltammetric using stannum film modified carbon paste electrodes (SnF-CPEs) in acetate buffer of solution pH 3.6. The electrochemical response of copper was apparently improved by stannum due to the enhanced accumulation of copper at the electrode surface. In comparison with the bare carbon paste electrode, the SnF-CPE was proved to be more sensitive, in addition, the stripping peaks of stannum and copper do not overlap with each other. The experimental parameters including the concentrations of Sn(II), pH of measure solution, deposition potential and deposition time were investigated and optimized. Under optimized conditions, the peak current was proportional to the concentration of Cu(Ⅱ) in the range of 1.0-75.0μg L-1 (r=0.998) with the detection limit of 0.50μg L-1. Application of the new electrode for the determination of copper in river water samples gave good results.更多还原