掺杂多壁碳纳米管改性聚溴甲酚绿膜修饰电极的制备、表征与应用研究

研究了掺杂多壁碳纳米管(MWNT)改性聚溴甲酚绿膜(PBG),以不同修饰方法制备了4种修饰电极,用扫描电镜、交流阻抗及循环伏安法等对电极进行表征。结果表明:4种修饰电极的电活化面积均得到明显提高,其中以层层修饰制备的聚溴甲酚绿膜/多壁碳纳米管复合膜(PBG/MWNT/GC)电极最能发挥MWNT和PBG的电活性。将电极用于8-羟基喹啉(8-HQ)电化学行为的研究,结果表明:4种修饰电极的伏安响应明显提高,且8-HQ在PBG/MWNT/GC上的氧化峰电位负移最多,峰电流最大,约为裸玻碳电极的4.5倍,电催化作用显著增强。8-HQ在PBG/MWNT/GC上电极反应的电子转移数和质子数均为1,是吸附控制的不可逆电氧化过程,氧化峰电流Ip与浓度c在4.0×10-6～3.5×10-4mol/L范围内呈良好的线性关系,r=-0.997 2,检出限(S/N=3)为1.96×10-8mol/L。PBG/MWNT/GC修饰电极可实现8-HQ的快捷、简便测定。

Preparation,Characterization and Application of Doped Multi-walled Carbon Nanotubes Modified Polybromocresol Green Film Modified Electrode

Multi-walled carbon nanotubes(MWNT) were doped to modify polybromocresol green film(PBG),and four kinds of modified electrodes were prapared by different modification methods.The modified electrodes were characterized by scanning electron microscopy,AC impedance and cyclic voltammery.The results indicated that the electrical activation areas were increased significantly at the four kinds of modified electrodes,in which the polybromocresol green film/multi-walled carbon nanotube composite film(PBG/MWNT/GC) electrode was the best one to develep the electric activity of MWNT and PBG.The electrode was applied in the study of the electrochemical behavior of 8-hydroxyquinoline(8-HQ),and the voltammetric response of 8-HQ on the four modified electrodes were improved significantly.Among them,the potential of oxidation peak of 8-HQ on PBG/MWNT/GC was shifted negatively and its peak current was the largest(about 4.5 times on that of the bare glass carbon electrode),indicating that the electric catalysis of 8-HQ on PBG/MWNT/GC was largely enhanced.The reaction of 8-HQ on PBG/MWNT/GC electrode was adsorption-controlled irreversible electro-oxidation process,and its numbers of electron transfer and proton were both 1.A good linear relationship was observed between peak current and concentration of 8-HQ in the range of 4.0×10-6-3.5×10-4 mol/L(r=-0.997 2) with a detection limit(S/N=3) of 1.96×10-8 mol/L.PBG/MWNT/GC is avaible to determine 8-HQ quickly and easily.