基于银、钯纳米粒子表面催化的硫离子分析方法研究

发布时间：2018-10-19 13:17

【摘要】：近年来,贵金属纳米粒子因其独特的光学和电学性质,在催化、药物输送、成像、医学诊断和治疗、生物传感、环境分析等研究领域引起广泛关注。本论文基于贵金属纳米粒子的表面催化活性,建立了一种以贵金属纳米粒子作为分析探针定量检测水中硫离子浓度的新方法。该方法灵敏度高、选择性好,且实现了硫离子的快速检测。实验中,我们首先利用多元醇热法制备了粒径均一(15 nm)、在水溶液中稳定分散的球形银纳米粒子。研究发现,该银纳米对硼氢化钠还原对硝基苯酚这一反应具有较强的催化作用;当在体系中加入不同浓度的硫氢化钠溶液,使得银纳米粒子表面被部分或全部硫化(即催化剂中毒),从而抑制银纳米粒子对该反应的催化活性,降低反应速率。通过反应速率常数与硫氢化钠浓度之间的定量关系建立了水中硫离子的检测新方法。该方法的检测范围为0.5 7.5μmol/L,且成功应用于实际样品的检测。其次,基于贵金属钯超高的催化活性,我们合成了不同形貌(立方体、八面体)的钯纳米粒子作为分析探针,催化过氧化氢氧化3,3,5,5-四甲基联苯胺(TMB)这个典型的催化氧化显色反应,建立了一种检测硫离子的高灵敏比色分析方法。实验中,我们首先使用边长为18 nm的钯纳米立方体作为探针,在室温条件下催化该反应。当在体系中加入不同浓度的硫氢化钠,使得钯纳米立方体表面被部分或全部硫化(即催化剂中毒),从而抑制钯纳米立方体对该反应的催化活性,降低反应速率。通过TMB在650 nm处的吸光度值与硫离子浓度之间的定量关系,建立了检测硫离子的新方法。此外,我们还对比考察了具有不同表面晶面的八面体钯纳米粒子对该反应的催化作用以及对分析方法灵敏度的影响。总之,本论文将贵金属纳米粒子的表面催化中毒效应与分析化学有机结合起来,并建立了检测水环境中硫离子浓度的新方法。该方法具有操作简便、响应快速、灵敏度高、选择性高等优点。
[Abstract]:In recent years, noble metal nanoparticles have attracted much attention in the fields of catalysis, drug delivery, imaging, medical diagnosis and treatment, biosensor and environmental analysis for their unique optical and electrical properties. Based on the surface catalytic activity of noble metal nanoparticles, a new method for quantitative determination of sulfur ion concentration in water using noble metal nanoparticles as analytical probe was developed. The method has the advantages of high sensitivity, good selectivity and rapid detection of sulfur ions. In the experiment, we first prepared spherical silver nanoparticles with uniform particle size (15 nm),) and stable dispersion in aqueous solution by polyol thermal method. It was found that the silver nanoparticles had a strong catalytic effect on the reduction of p-nitrophenol by sodium borohydride. The surface of silver nanoparticles was partially or completely sulfided (i.e. catalyst poisoning), which inhibited the catalytic activity of silver nanoparticles and reduced the reaction rate. A new method for the determination of sulfur ions in water was established by the quantitative relationship between the reaction rate constant and the concentration of sodium sulphide. The detection range of this method is 0. 5 渭 mol/L, and has been successfully applied to the detection of real samples. Secondly, based on the high catalytic activity of noble metal palladium, we synthesized palladium nanoparticles with different morphologies (cubes, octahedrons) as analytical probes. A highly sensitive colorimetric analysis method for the determination of sulfur ions was established by catalytic oxidation of hydrogen peroxide to 3 ~ (3) O _ (3) O _ (5) tetramethyl benzidine (TMB) as a typical catalytic oxidation reaction. In the experiment, the palladium nanocrystals with side length of 18 nm were first used as probes to catalyze the reaction at room temperature. When different concentrations of sodium sulphide were added to the system, the surface of the palladium nanocube was partially or completely sulfided (i.e. catalyst poisoning), which inhibited the catalytic activity of the nanocrystalline palladium cube and reduced the reaction rate. Based on the quantitative relationship between the absorbance of TMB at 650 nm and the concentration of sulfur ions, a new method for the determination of sulfur ions was established. In addition, the catalytic effect of octahedral palladium nanoparticles with different surface faces on the reaction and the sensitivity of the analytical method were investigated. In this paper, the surface catalytic poisoning effect of noble metal nanoparticles was combined with analytical chemistry, and a new method for the determination of sulfur ion concentration in water was established. This method has the advantages of simple operation, fast response, high sensitivity and high selectivity.
【学位授予单位】：重庆师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TB383.1

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