碳纤维基PbO2电极的制备及其对吡啶的电化学氧化行为.doc

PAGE PAGE 21 碳纤维基PbO2电极的制备及其对吡啶的电化学氧化行为 摘要：含氮杂环化合物结构稳定且具有生物毒性以及潜在三致性对环境保护和人类健康造成威胁，电化学氧化法灵敏度高，省时，操作简单，可检测和降解该类污染物，其核心是制备高性能修饰电极。碳纤维具有比表面积大、导电性能优良、化学稳定性好以及廉价等优势，利用碳纤维承载二氧化铅是改善电极性能的一种方法。本文以碳纤维粉末为基材，通过优化计时电沉积法制备碳纤维基PbO2修饰电极(PbO2/CFs/GC)，考察了吡啶在玻碳电极（GC）、碳纤维基玻碳电极（CFs/GC）和PbO2/CFs/GC上的响应，结果表明，吡啶在电沉积20 min时制得的PbO2/CFs/GC电极上响应最强。以吡啶为研究对象，铂丝为辅助电极，饱和甘汞电极（SCE）为参比电极，工作电极为碳纤维基 PbO2修饰电极，采用线性扫描伏安法考察吡啶在不同支持电解质、初始pH、扫描速率和吡啶浓度条件下在碳纤维基PbO2修饰电极上电化学行为，获得吡啶的最佳响应条件为：支持电解质为5 g/LNa2SO4，在吡啶初始pH为7.9，扫描速率为25 mV/s的条件下，线性响应范围是0-1000 mg/L。吡啶在PbO2/CFs/GC电极上的氧化反应同时受到吸附控制和扩散控制。 关键词：碳纤维；二氧化铅；修饰电极；吡啶 PREPARATION OF CARBON FIBER BASED LEAD DIOXIDE ELECTRODE AND ELECTROCHEMICAL OXIDATION BEHAVIOR OF PYRIDINE Abstract: Nitrogen heterocyclic compound is difficult to be degraded in the natural environment due to its stable structure, biological toxicity, potential teratogenicity, carcinogenicity and mutagenicity. Electrochemical oxidation method has high sensitivity, time saving, easy operating and can detect and degrade the pollutants, its core is the preparation of high-performance modified electrodes. Carbon fiber can be used as the substrate to improve the performance of PbO2 electrode due to its large surface area, good electrical conductivity, cost-effective and so on. In this study, carbon fiber powder was selected as the substrate to support PbO2 by electrodeposition. The behavior of pyridine on glassy carbon electrode(GC), carbon fiber glassy carbon electrode (CFs/GC), carbon fiber based lead dioxide glassy carbon electrode (PbO2/CFs/GC) were also investigated, the results showed that PbO2/CFs/GC prepared after 20 min of deposition has the strongest response for pyridine. Pyridine was selected as model pollutant to investigate the electrochemical oxidation behaviors on PbO2/CFs/GC using linear sweep voltammetry (LSV) with an electrochemical workstation (CHI 660C). Saturated calomel electrode, Pt wire electrode and carbon fiber supported PbO2 electrode were used as the reference, counter and wor