Li~+/TiO_2/ITO工作电极的制备及其异相反应动力学特性

采用溶胶-凝胶法在ITO导电玻璃基片表面制备一层TiO2薄膜,将其作为工作电极,与作为参比电极的饱和甘汞电极、作为辅助电极的铂黑电极、作为电解质溶液的碳酸丙烯酯+高氯酸锂一起构成三电极测试体系.采用原子力显微镜和X射线衍射仪对薄膜进行了表征,测试了在电极电势分别在±0.5 V,±1.0 V和±2.0 V时的循环伏安曲线.结果表明,扫描电位在±2 V时,循环伏安曲线出现明显的Li+注入峰和抽出峰,Li+在电解质溶液和TiO2层中的扩散速度是电极过程动力学的决速步骤;而扫描电位在±1 V和±0.5 V时,循环伏安曲线没出现Li+注入峰和抽出峰,工作电极电位是电极过程动力学的决速步骤;研究工作电极的...

Preparation of Li~+/TiO_2/ITO Working Electrode and Its Kinetics Characteristics of Heterophase Reaction

The working electrode was prepared by way of depositing TiO2 thin film on conductive ITO glass substrate via sol-gel method. As 3-electrode testing system was then formed combining it with SCE (saturated calomel electrode) as reference one, black platinum electrode as auxiliary one and PC + LiClO4 solution as electrolyte. The TiC2 thin film was characterized by AFM, SEM and XRD to test the cyclic volt-ampere characteristic curves of the potential of the working electrode at the scanning voltages ± 0.5 V, ± 1.0 V and ± 2.0 V. Testing results showed that on the curve at ± 2.0 V the Li⁺ inserting and extracting peaks appear clearly and that the Li⁺ plays a role as a rate determining step in the electrode process kinetics of the diffusion rate in the electrolyte and TiC2 thin film. However, no Li⁺ inserting and extracting peaks appear on the curves at ± 1.0V and ± 0.5 V. It implies that the potential of working electrode is the rate determining step of the electrode process kinetics. A conclusion is drawn that the scanning potential should be greater than ± 2.0 V when studying the characteristics of heterophase reaction kinetics.