纳米电极稳态电流表征的探讨

发布时间：2019-04-20 14:07

【摘要】：稳态循环伏安法具有简单、快速判别电极性能和估算电极尺寸的特性,因而被广泛应用于超微电极的表征.但纳米电极由于尺寸极小,其表面形貌的细微变化对电化学行为有明显的扰动,从而影响纳米电极表征的准确性.结合电化学实验和有限元模拟,探讨了纳米电极尺寸、绝缘层半径和电极半径之和与电极半径之比(RG)和尖端孔道对稳态电流的影响.研究表明尺寸较小(r≤80 nm)的纳米圆盘电极,由于反应速率相对扩散较慢,电极反应过程受动力学效应控制,使稳态电流曲线偏离半球形扩散控制的标准"S"型.此外RG值较小的纳米圆盘电极,物质到电极的传递被增强,使极限电流值增大.我们对内嵌式纳米电极进行了进一步研究,并发现电极尖端孔道阻碍了电活性物质的扩散,削弱了动力学的限制,使极限电流值低于同尺度的纳米圆盘电极,伏安电流曲线呈现标准的"S"型.本研究系统地探讨了电极尖端形貌与稳态电流的相互关系,加深了对纳米电极电化学行为的理解.
[Abstract]:Steady-state cyclic voltammetry has been widely used in the characterization of ultra-micro electrodes because of its simple and rapid identification of electrode performance and estimation of electrode size. However, due to the very small size of the nano-electrode, the surface morphology of the nano-electrode has obvious disturbance to the electrochemical behavior, which affects the accuracy of the characterization of the nano-electrode. Based on the electrochemical experiments and finite element simulation, the effects of the size of the nano-electrode, the ratio of the insulator radius, the sum of the electrode radius and the electrode radius to the electrode radius (RG) and the tip channel on the steady-state current were investigated. The results show that for the nano-disk electrode with smaller size (r 鈮，

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