纳米氢氧化钴修饰碳糊电极检测百菌清及其量化计算和交流阻抗  

Determination and Quantum Chemical,Electrochemical Studies of Chlorothalonil at Nanoparticle Cobalt Hydroxide Modified Carbon Paste Electrode

作　　者：王佳 朱永春[2] 那宝双 辛士刚 张洪波 WANG Jia;ZHU Yong-chun;NA Bao-shuang;XIN Shi-gang;ZHANG Hong-bo(College of Chemistry and Chemical Engineering,Shenyang Normal University, Shenyang 110034, China;Institute of Catalysis for Energy and Environment,Shenyang Normal University, Shenyang 110034, China)

机构地区：[1]沈阳师范大学化学化工学院,沈阳110034 [2]沈阳师范大学能源与环境催化研究所,沈阳110034

出　　处：《科学技术与工程》2019年第14期6-13,共8页Science Technology and Engineering

基　　金：国家科技部国际合作重大项目(2004DFA02700);国家自然科学基金(20875063);辽宁教育厅项目(2004-c022);国家电分析重点实验室项目(2006-06);沈阳市科技局基金(2007-GX-32)资助

摘　　要：百菌清是一种高效、低毒的有机氯杀菌剂,对多种作物的真菌病害有良好的预防作用;由于其可以黏附在植物上或经过植物进入饮用水中,因此对人类健康产生潜在危害。运用微分脉冲伏安(DPV)方法通过修饰碳糊电极检测了百菌清。首先运用电化学方法将氢氧化钴恒电位沉积到碳糊电极表面。在电极电压的作用下,百菌清分子被萃取到电极表面,百菌清与氢氧化钴相互作用形成络合物,在-0. 66 V处得到一个还原峰。还原峰电流与随扫速呈一次方正增长关系,证明还原过程受吸附控制。吸附过程满足Temkin等温吸附模型,反应ΔGr为-3 929. 94 k J/mol,可以自发进行。运用量化计算和交流阻抗的方法探究了反应过程,计算所得结果与电化学实验所得结果相一致。因此可以用该体系来检测百菌清。还原峰电流与百菌清浓度的对数在3. 333×10-5~3. 333×10-12mol/L范围内呈线性关系,检出限信噪比(S/N=3)达到3. 333×10-12mol/L。该方法具有较好的选择性;用于污水中百菌清的检测,其结果令人满意。Chlorothalonil is an efficient and common organochlorine fungicide. It has a good preventive effect on fungal diseases of many vegetables,fruit trees,small plants and other crops. Since it can attach to plants or pass through plants into drinking water,it is potentially harmful to human health. Chlorothalonil was detected by Different Pulse Voltammetry( DPV) method with nanoparticle cobalt hydroxide modified on carbon paste electrode. At first,cobalt hydroxide was deposited on the surface of carbon paste electrode at the constant applied potential. Under the applied potential,chlorhexidine molecules were extracted onto the electrode surface and it interacted with cobalt hydroxide to form a complex and made a reduction peak at-0. 66 V. The reduction peak current increases linearly with the increase of scan rate indicating the reduction reaction controlled by surface adsorption. The adsorption behavior follows a Temkin isothermal adsorption model. Adsorption free energy of the reduction reaction is-3 929. 94 kJ/mol which proves the reduction reaction is spontaneous. Quantum chemical and electrochemical impedance spectroscopy method is used to explore the reaction process,the result shows a good consistency with the experimental results. Therefore,the system can be used to detect chlorothalonil. The reduction peak current is linear changed with the logarithm of chlorothalonil concentration in the range of 3. 333 × 10-5~ 3. 333 × 10-12 mol/L,which can be used to determine the concentration of chlorothalonil with the limits of detection( S/N = 3) of 3. 333 × 10-12 mol/L. The method has good selectivity. It has been applied to the determination of chlorothalonil in sewage with satisfactory results.

关 键 词：氢氧化钴 碳糊电极 百菌清 量化计算 交流阻抗 

分 类 号：O643.36[理学—物理化学]