纳米铜及纳米铜—石墨烯复合物在硝酸盐氮检测方面的应用

发布时间：2018-10-31 16:27

【摘要】：硝酸盐氮是所有含氮物质氧化分解的最终产物，环境介质中的硝酸盐氮对生物循环起着非常重要的作用。硝酸盐氮可转化为亚硝酸盐氮，间接对机体造成急性危害；水环境中硝酸盐氮浓度的升高可直接导致水体出现富营养化现象。本研究主要通过在电极表面电沉积金属铜纳米粒子的方法来实现对水环境中硝酸盐氮含量的检测，最终建立了硝酸盐氮的浓度与电化学响应信号之间的线性关系，并初步应用于水环境中硝酸盐氮含量的检测。本研究由以下两部分组成：第一部分：基于金属铜纳米颗粒的硝酸盐氮电化学传感器的研究研究中采用计时电流法将铜纳米颗粒直接电沉积到玻碳电极表面，再用循环伏安法对标准溶液中的硝酸盐氮含量进行检测。研究结果表明，硝酸盐氮在纳米铜修饰的玻碳电极上出现还原峰，且还原峰电流与硝酸盐氮浓度线性相关，，可作为硝酸盐氮的检测信号。研究中探讨了多种因素对检测结果的影响。在最优实验条件下，该传感器对硝酸盐氮的检测线性范围为2.0×10-5~2.0×10-2mol/L,检出限为1.0×10-5mol/L。该硝酸盐氮传感器还对氯离子和磷酸根离子表现出良好的抗干扰能力。第二部分：基于纳米铜-石墨烯复合物的硝酸盐氮电化学传感器的研究本研究中先将纳米材料——石墨烯修饰于玻碳电极表面，再用计时电流法将纳米铜电沉积到石墨烯修饰的玻碳电极表面，使用循环伏安法实现了对硝酸盐氮含量的检测。纳米铜的良好还原性以及石墨烯的优良电化学特性使该电化学传感器在硝酸盐氮检测方面表现出良好的灵敏度和稳定性。通过探讨多种实验因素对检测结果的影响，在最优实验条件下，得到该传感器对硝酸盐氮的检测线性范围为1.0×10-6~5.0×10-3mol/L，检出限为5.0×10-7mol/L。该传感器对实际淡水水样中硝酸盐氮含量的检测结果与国家标准方法（紫外分光光度计）的检测结果具有良好的一致性。
[Abstract]:Nitrate nitrogen is the final product of the oxidation and decomposition of all nitrogen-containing substances. Nitrate nitrogen in environmental media plays a very important role in the biological cycle. Nitrate nitrogen can be transformed into nitrite nitrogen, which indirectly causes acute harm to the body, and the increase of nitrate nitrogen concentration in water environment can directly lead to eutrophication of water body. In this study, the content of nitrate nitrogen in water environment was detected by electrodeposition of metal copper nanoparticles on the electrode surface, and the linear relationship between nitrate nitrogen concentration and electrochemical response signal was established. It was applied to the determination of nitrate nitrogen in water environment. This study consists of the following two parts: the first part: in the study of nitrate-nitrogen electrochemical sensor based on metal copper nanoparticles, copper nanoparticles were electrodeposited directly to glassy carbon electrode surface by chronoamperometric method. The content of nitrate nitrogen in standard solution was determined by cyclic voltammetry. The results showed that the reduction peak of nitrate nitrogen appeared on the nanocrystalline copper modified glassy carbon electrode, and the reduction peak current was linearly correlated with the nitrate nitrogen concentration, which could be used as the detection signal of nitrate nitrogen. The influence of many factors on the test results was discussed. Under the optimal experimental conditions, the linear range of the sensor for the detection of nitrate nitrogen is 2.0 脳 10 ~ (-5) 渭 mol / L and the detection limit is 1.0 脳 10 ~ (-5) mol / L. The nitrate nitrogen sensor also shows good anti-interference ability to chloride ion and phosphate ion. The second part: the study of nitrate-nitrogen electrochemical sensor based on nano-copper-graphene composite. In this study, the nano-material graphene was first modified on the surface of glassy carbon electrode. Nanocrystalline copper was electrodeposited on the surface of glassy carbon electrode modified with graphene by chronoamperometric method. The content of nitrate nitrogen was determined by cyclic voltammetry. The good reduction of nano-copper and the excellent electrochemical characteristics of graphene make the electrochemical sensor show good sensitivity and stability in nitrate nitrogen detection. By studying the influence of many experimental factors on the detection results, under the optimal experimental conditions, the linear range of the sensor for nitrate nitrogen detection is 1.0 脳 10-6N 5.0 脳 10-3 mol / L, and the detection limit is 5.0 脳 10-7 mol / L. The sensor has good agreement with the national standard method (ultraviolet spectrophotometer) for the determination of nitrate nitrogen in fresh water samples.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R123.1;O657.1

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