硫化钠在旋转圆盘电极上电化学氧化动力学行为

摘要

采用旋转圆盘电极研究了硫化钠电化学氧化动力学行为，并通过同步摄像装置监测了电极表面的硫沉积斑图。研究发现，旋转电极能削弱电极表面活性物种的浓度梯度，弱化N-NDR振荡的负反馈，从而使得N-NDR振荡转变为稳态；然而电极表面沉积硫增多，抑制硫离子的电化学氧化，增强了吸附负反馈，有利于HN-NDR振荡的产生。%The dynamical behavior of electrochemical oxidation of sodium sulfide was investigated by using rotating disk electrode. Pattern formation of sulfur deposition on the disk was simultaneously monitored with a camera device. The results indicated that the active species concentration gradient at the surface of electrode was weakened as the disk rotating as well as the negative feedback for the N-NDR oscillations, which as a result made the N-NDR oscillations into the steady state. However, with the disk rotating the sulfur depositing on the electrode surface increased, as a result the electrochemicaloxidation of sulfide was suppressed and the adsorption negative feedback was enhanced, which consequently was beneficial to the HN-NDR oscillations.