聚合物/碳纳米管网孔结构负载硅钨酸修饰电极检测水中溴酸盐  

Sensitive Determination of Bromate in Water by Using a Modified Electrode Based on Polymer/Carbon Nanotubes Mesh Structure Loaded Silicotungstic Heteropolyanion

作　　者：黄大凯[1] 薛琳[1] 曹忠[1] 李旭[1] 肖忠良[1] 郑卓[1] 谭淑珍[1] 杨荣华[1] 

机构地区：[1]长沙理工大学化学与生物工程学院电力与交通材料保护湖南省重点实验室微纳生物传感与食品安全检测协同创新中心,长沙410004

出　　处：《分析化学》2015年第11期1664-1670,共7页Chinese Journal of Analytical Chemistry

基　　金：国家科技支撑计划(No.2012BAC17B01);国家自然科学基金(Nos.21275022;21545010;31527803);湖南省科技计划(No.2013FJ3075)项目资助~~

摘　　要：通过电聚合和电沉积,将聚邻苯二胺（Po PD）/酸化多壁碳纳米管（MWNTs）网孔结构支撑的硅钨酸（Si W12）杂多阴离子成功地组装在玻碳电极（GCE）上,形成Si W12/Po PD/MWNTs/GCE。采用扫描电子显微镜和循环伏安法对不同电极复合膜进行表征,并考察Br O-3在电极上的电化学行为,发现Si W12/Po PD/MWNTs/GCE对Br O-3具有显著的电催化还原性,其作用机理是基于硅钨酸杂多阴离子复合膜在电化学还原Br O-3过程中,通过静电作用将Br O-3吸附到电极的表面,Br O-3在电极表面接受H＋和硅钨酸失去的电子,依次被还原为HBr O、Br2、Br-。该电极在0.20 mol/L磷酸盐缓冲溶液（p H=3.0）中,Br O-3的线性范围为1.0×10-8~1.0×10-4mol/L,检出限达7.0×10-9mol/L。此电极选择性、重现性、稳定性好,可用于实际水样中Br O-3检测,回收率在98.4%~104.1%之间,且与离子色谱方法检测结果一致,符合国家标准对水中溴酸盐的检测要求。Through electro-polymerization and electro-deposition,a poly（ o-phenylenediamine）（ Po PD） /acidified multi-wall carbon nanotubes（ MWNTs） mesh structure supported silicotungstic heteropolyanion was successfully assembled on a glassy carbon electrode（ GCE）,forming a Si W12/ Po PD / MWNTs / GCE. Scanning electron microscopy（ SEM） and cyclic voltammetry（ CV） were employed to characterize the different composite films. The electrochemical behaviors of bromate ion（ Br O-3） on the surfaces of different modified electrodes were investigated,indicating that the proposed Si W12/ Po PD / MWNTs / GCE exhibited excellent electrocatalytic reduction activity to bromate. The mechanism is that the bromate anion is adsorbed to the surface of the electrode through electrostatic interaction,and accepts H＋and electrons lost from Si W12 on the surface,resulting in its stepwise reduction to HBr O,Br2,and Br-. In 0.20 mol / L phosphate buffer solution（ p H= 3.0）,the modified electrode showed excellent electrochemical response property to Br O-3with a linear range of 1.0×10-8~ 1. 0 × 10-4mol / L and a detection limit of 7. 0 × 10-9mol / L. The electrode possessed good selectivity,reproducibility and stability,which can be well applied to determination of bromate content in real water samples with a recovery of 98.4%-104.1%. The accuracy of the electrode was also comparable to that of a traditional ion chromatographic method,which met the national standard for requirement of bromate detection in water,indicating that the proposed method was of valuable in practical application on fields of food safety and environmental protection.

关 键 词：硅钨酸杂多阴离子 碳纳米管 网孔结构 溴酸盐 水质检测 

分 类 号：O657.1[理学—分析化学]