聚乙烯醇/酸化碳纳米管高亲水性三维孔电极膜的制备与电化学性能

摘要

On the basis of moderate acidification of multiwalled carbon nanotubes ( MWCNTs), polyvinyl alcohol(PVA) / a-MWCNTs hydrogel electrode membrane with three-dimensional nanohole was prepared by electrophoretic deposition technology and cycle freeze-thaw process. The electrode membrane has high electrical activity area, low surface charge transfer resistance, high hydrophilicity and low mass transport resistance. The electric catalytic reduction peaks of dopamine on the PVA/ a-MWCNTs hydrogel membrane-modified electrode is not affected by ascorbic acid in cyclic voltammetry test. Dopamine can be determined by the feature of the electrode membrane in the presence of excessive ascorbic acid. The linear interval of dopamine concentration was 2 × 10-6—2 × 10-3 mol/ L, the threshold of detection concentration can reach 10-6 mol/ L and the sensitivity can reach 12. 3 μA/ ( mmol·L-1 ). The electrode membrane also has good stability for dopamine detection.%在酸化碳纳米管的基础上,采用电泳沉积和冷冻-解冻循环交联工艺制备了高亲水性聚乙烯醇/酸化碳纳米管(PVA/ a-MWCNTs)水凝胶电极膜.该电极膜具有三维连通纳米孔结构,同时还具有高电活性面积、低表面电荷传递电阻以及良好的扩散通透性等电化学特性.该电极膜对多巴胺(DA)有很好的电化学响应特性,并且对多巴胺的电化学还原电流不受抗坏血酸(AA)干扰,在过量抗坏血酸存在下, PVA/ a-MMWCNTs水凝胶电极膜对多巴胺还原电流的一阶导数与多巴胺的浓度在2×10-6~2×10-3 mol/ L 范围内呈线性关系,检出限达到1×10-6 mol/ L,灵敏度达到12.3μA/(mmol·L-1),同时还表现出了较好的电极稳定性和重现性.