论文部分内容阅读
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.
Steady-state cyclic voltammetry has been widely applied to the characterization of ultra-microelectrodes because of its simple and rapid characterization of electrode performance and electrode size estimation. However, due to its extremely small size, the slight changes in its surface morphology affect the electrochemical behavior The results show that the ratio of the sum of the electrode size, the radius of the insulator and the electrode radius to the radius of the electrode (RG) State current.The research shows that the nanosized disk electrode with smaller size (r≤80 nm) has a relatively slow diffusion of the reaction rate and the electrode reaction process is controlled by the kinetic effect, which makes the steady-state current curve deviate from the hemispherical diffusion control Standard “S ” type.In addition, the smaller the RG value of the nanodisc electrode, the substance to the electrode transfer is enhanced, so that the limiting current value increases.We conducted further research on the embedded nano-electrode and found that the electrode tip The pores impede the diffusion of electroactive substances and weaken the limitation of the kinetics, so that the limiting current value is lower than that of the nanoscale disk electrode on the same scale. The voltammetric current curve shows a standard “S” shape. The relationship between the tip morphology and the steady state current was systematically investigated, which deepened the understanding of the electrochemical behavior of the nano-electrode.