修饰玻碳电极的制备及其在环境污染物检测中的应用

发布时间：2018-09-18 11:14

【摘要】：利用化学修饰电极进行检测的电化学方法有着快速响应、仪器廉价、体积小、电极制备过程简单、灵敏度高、重现性好以及成本低等优点,一直是电化学领域的研究热点。本文报告了以多壁碳纳米管、纳米金溶液和孔雀石绿等为原料,分别采用滴涂法和电化学聚合的方法制备了三种化学修饰电极:羧基化多壁碳纳米管/壳聚糖修饰玻碳电极(c-MWCNTs/CS GCE)、羧基化多壁碳纳米管-纳米金/壳聚糖修饰玻碳电极(c-MWCNTs-Au/CS GCE)和聚孔雀石绿修饰玻碳电极(PMG/GCE),并研究了水环境污染物2,4-二氯酚、亚硝酸盐和正磷酸盐的检测方法其在电极上的电化学行为。内容如下:(1)c-MWCNTs/CS GCE检测水体中的2,4-二氯酚:通过滴涂法制备c-MWCNTs/CS GCE,采用循环伏安法和差分脉冲伏安法研究了2,4-二氯酚在该修饰电极上的电化学行为。实验结果表明:与裸玻碳电极相比,c-MWCNTs/CS GCE明显提高了2,4-二氯酚的氧化峰电流,且2,4-二氯酚在修饰电极上发生的电化学反应是一个两电子和两质子参与受扩散控制的完全不可逆反应。2,4-二氯酚在该检测条件下的扩散系数D为1.5857×10~(-5) cm~2·s~(-1)。采用循环法安法对2,4-二氯酚检测:线性检测范围为0.2-1.0 mg/L、1.0-10 mg/L和10-80 mg/L,拟合R~20.99,检测限为0.1mg/L。采用差分脉冲伏安法检测2,4-二氯酚:线性检测范围0.1-1mg/L、1-10 mg/L和10-80 mg/L,R~20.99,检测限为0.01 mg/L。(2)c-MWCNTs-Au/CS GCE检测水体中的亚硝酸盐:采用滴涂法制备c-MWCNTs-Au/CS GCE,并用循环伏安法和差分脉冲伏安法研究亚硝酸盐在修饰的电极上的电化学行为。实验结果表明:c-MWCNTs-Au/CS GCE对亚硝酸盐具有显著的电催化作用。亚硝酸根在修饰电极上发生的电化学反应是一个有两个电子参与而无质子参与的完全不可逆氧化反应,且该反应过程受扩散控制。在检测条件下,亚硝酸钠的扩散系数为2.6403×10~(-6) cm~2·s~(-1)。采用循环伏安法检测亚硝酸盐:线性检测范围为0.8-10 mg/L和10~(-5)00 mg/L,R~20.99,检测限为0.1 mg/L。差分脉冲伏安法检测亚硝酸盐:线性检测范围为0.05-1 mg/L和1-150 mg/L,R~20.99,检测限为0.01 mg/L。(3)磷酸盐在PMG/GCE上的电化学行为研究:采用循环伏安法电化学聚合孔雀石绿制备PMG/GCE,并用循环伏安法和差分脉冲伏安法研究磷钼酸在修饰电极上的电化学行为。实验结果表明:PMG/GCE对磷钼酸的电催化作用显著强于GCE,磷钼酸在修饰电极上发生的电化学反应是多个准可逆反应组成,每一个可逆反应均有两电子和两质子参与,反应受扩散控制,磷钼酸在检测条件下的扩散系数D为7.258502×10~(-6) cm~2·s~(-1)。循环伏安检测:线性检测范围:0.1-1 mg/L和1-12 mg/L,R~20.99,检测限为0.04 mg/L。差分脉冲伏安检测:线性检测范围0.08-1 mg/L和1-12 mg/L,R~20.99,检测限为0.01 mg/L。
[Abstract]:The electrochemical method using chemically modified electrode has the advantages of rapid response, cheap instrument, small volume, simple preparation process, high sensitivity, good reproducibility and low cost. In this paper, multiwalled carbon nanotubes, gold nanoparticles and malachite green are used as raw materials. Three chemically modified electrodes, carboxylated multiwalled carbon nanotubes / chitosan modified glassy carbon electrodes (c-MWCNTs/CS GCE), carboxylated multiwalled carbon nanotubes) and gold / chitosan modified glassy carbon electrodes were prepared by drop coating and electrochemical polymerization. Electrode (c-MWCNTs-Au/CS GCE) and poly (malachite green) modified glassy carbon electrode (PMG/GCE). Methods for determination of nitrite and orthophosphate. Electrochemical behavior of nitrite and orthophosphate on electrode. The main contents are as follows: (1) c-MWCNTs/CS GCE was used to detect 2H _ 4-dichlorophenol in water. The electrochemical behavior of 2H _ 4-dichlorophenol on the modified electrode was studied by cyclic voltammetry and differential pulse voltammetry. The results show that compared with bare glassy carbon electrode, c-MWCNTs / CS GCE significantly increases the oxidation peak current of 2% 4-dichlorophenol. Moreover, the electrochemical reaction of 2o 4- dichlorophenol at the modified electrode is a completely irreversible reaction controlled by diffusion with two electrons and two protons. The diffusion coefficient D is 1.5857 脳 10 ~ (-5) cm~2 s ~ (-1). The linear detection range was 0.2-1.0 mg/L,1.0-10 mg/L and the 10-80 mg/L, fitting rn was 20.99. The detection limit was 0.1 mg 路L ~ (-1) 路L ~ (-1). Detection of nitrite in water by differential pulse voltammetry: linear detection ranges from 0.1 to 1 mg / L ~ (10) mg/L and 10 ~ (- 80) mg/L,R~20.99, to 0. 01 mg/L. (2) c-MWCNTs-Au/CS GCE: preparation of c-MWCNTs-Au/CS GCE, by drop coating and preparation of c-MWCNTs-Au/CS GCE, by cyclic voltammetry and differential pulse voltammetry Electrochemical behavior of nitrite on modified electrode. The experimental results show that the GCE of c-MWCNTs-Aur / CS has a remarkable electrocatalytic effect on nitrite. The electrochemical reaction of nitrite on the modified electrode is a completely irreversible oxidation reaction with two electrons and no protons, and the reaction process is controlled by diffusion. The diffusion coefficient of sodium nitrite is 2.6403 脳 10 ~ (-6) cm~2 s ~ (-1). Determination of nitrite by cyclic voltammetry: the linear detection range is 0.8-10 mg/L and the detection limit of 10 ~ (-5) 00 mg/L,R~20.99, is 0.1 mg/L.. Detection of nitrite by differential pulse voltammetry: linear detection range of 0.05-1 mg/L and detection limit of 1-150 mg/L,R~20.99,: electrochemical behavior of phosphate on PMG/GCE: preparation of malachite green by cyclic voltammetry and cyclic polymerization of malachite green with cyclic voltammetry The electrochemical behavior of phosphomolybdic acid at modified electrode was studied by voltammetry and differential pulse voltammetry. The experimental results show that the electrocatalysis of molybdophosphoric acid by GCE, / PMG / GCE is significantly stronger than that of the electrochemical reaction of GCE, phosphomolybdic acid at the modified electrode. Each reversible reaction is composed of two electrons and two protons, and the reaction is controlled by diffusion. The diffusion coefficient of phosphomolybdic acid was 7.258502 脳 10 ~ (-6) cm~2 s ~ (-1). Cyclic voltammetry: linear detection range: 0. 01 mg/L and 1-12 mg/L,R~20.99, detection limit: 0. 04 mg/L. Differential pulse voltammetry: linear detection range 0.08-1 mg/L and 1-12 mg/L,R~20.99, detection limit 0. 01 mg/L.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X830;O646

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