聚苯胺对抗坏血酸的电催化氧化及磁效应

磁场对生物体系及其中物理现象和化学反应的影响历来是人们关注的焦点[1]．磁场能影响分子、细胞、组织、器官乃至整个生物体系的新陈代谢功能．磁场对化学反应的影响通常是通过对自由基（对）施加作用而体现的，磁场改变了未成对电子的自旋方式，从而改变了反应的墙，进而改变化学反应的速率[2]．此外，磁场对电化学体系的影响也有报导[3]，外加磁场激发溶液流动，产生磁流体动力学效应（MHD）[4]，增大传质速度，影响电化学进程．本文研究聚苯胺（PAN）修饰电极上抗坏血酸（AA）的电催化氧化，并讨论了膜厚、溶液pH值、AA浓度（CAA…

Electrocatalytic Oxidation of Ascorbic Acid at Polyaniline Modified Electrode and the Effects of the Magnetic Field

The electrocatalytic oxidation of ascorbic acid(AA) in H2SO4 solution at polyaniline(PAN) modified electrode was studied by cyclic voltammetry(CV). The electrocatalytic behavior was affected by the PAN film thickness(D), the pH values of solution, the AA concentration and the metalic cation. The results show that the peak current has good linear relationship with the AA concentration at pH=4.5, D=0.1μm in 1o-2 ~10-8mol?L-1 AA. The electrocatalytic activity was strengthened by Cu2+ and Fe2+ ions. The CV behavior was also investigated under the magnetic fields up to 0.7T(1T=104 Gauss). Plateaus of limiting currents were observed when the magnetic flux was directed in parallel to the surface of electrode. The phenomena were explained by the enhancement of mass transfer by magnetohydrodynamic (MHD) convection. The magnetic field effects was found to be pronounced at the slow potential scan rate of 10mv?s-1. But when the magnetic flux directed in perpendicular to the surface of electrode, the effect was not observed.