2,4,5-三氯苯酚在复合修饰电极的电化学行为的研究  

Electrochemical behavior and determination of 2,4,5-trichlorophenol based on the composite material modified electrode

作　　者：卫应亮[1] 王安亭[1] 王永刚[1] 赵丹[1] 

机构地区：[1]洛阳理工学院环境工程与化学学院,河南洛阳471023

出　　处：《化学研究与应用》2016年第9期1191-1196,共6页Chemical Research and Application

基　　金：国家自然科学基金项目(21203087)资助;河南省基础与前沿技术研究计划项目(122300410031)资助;河南省高等学校青年骨干教师计划项目(2009GGJS_123)资助

摘　　要：制备了多壁碳纳米管/纳米金复合修饰电极(MWCNT/Au NPs/GCE),研究了2,4,5-三氯苯酚(2,4,5-trichlorophenol,简称2,4,5-TCP)在此修饰电极上的电化学行为。结果表明2,4,5-三氯苯酚在MWCNT/Au NPs/GCE上于0.640V有一灵敏氧化峰,与裸电极相比峰电流显著提高。考查了支持电解液、修饰剂用量等测量条件的影响,发现在7.0×10^(-7)~6.0×10^(-6)mol·L^(-1),3.5×10^(-6)~3.5×10^(-4)mol·L^(-1)两个浓度区间内,2,4,5-TCP峰电流和浓度呈良好线性关系。在扫速0.05~0.2 V·s^(-1)时,氧化峰电流与扫速成线性关系,这说明2,4,5-TCP在修饰电极上的电化学氧化过程是受吸附控制的。采用计时电量法获得扩散系数(D)为3.08×10^(-6)cm^2·s^(-1);根据Frumkin等温式,计算出2,4,5-TCP的吸附系数β为1.3×10~3L·mol^(-1)。另外,我们推导出2,4,5-TCP在MWCNT/Au NPs/GCE修饰电极上的电极反应是一电子、一质子的完全不可逆过程。In this work,a novel modified electrode,namely,multi-walled carbon nanotubes/Au nano-particles modified glassy carbon electrode（ MWCNT/AuNPs/GCE） was developed, and the electrochemical behavior of 2,4,5-trichlorophenol（ 2,4,5-TCP） at this modified electrode was investigated systematically. A sensitive oxidation peak of 2,4,5-TCP was observed at the potential of 0. 640V on MWCNT/AuNPs/GCE. Compared with bare GCE,the peak current increases significantly. The effect factors of the electrochemical response of 2,4,5-TCP,such as the supporting electrolyte,the amount of modifier and so on were carefully optimized. Under the optimum conditions,two good linear relationships were obtained in the range of 7. 0×10 ^7 - 6. 0×10 ^ 6 mol·L4 and 3. 5×10 ^ 6 - 3. 5× 10^- 4 mol·L ^-1The oxidation peak current increases linearly with scanning speed in the range of 0. 05 - 0. 2 V·s ^- 1,which suggesting that the electrochemical oxidation process of 2,4,5-TCP on this modified electrode is absorption-controlled process. Based on chro nocoulometry result,the diffusion coefficient（ D） could be estimated and the result was 3. 08×10 ^-6 cm^2 ·s According to Frumkin adsorption isotherm equation,the absorption coefficient（ p） could be calculated,and the result was 1. 3×l0^3 L·mol Additionally, we proposed the oxidation of 2,4,5-TCP belongs to a one-electron and one-proton totally irreversible electrode process.

关 键 词：2 4 5-三氯苯酚 多壁碳纳米管 纳米金 修饰电极 伏安法 

分 类 号：O657.15[理学—分析化学]