Kinetics and Mechanisms for Photoelectrochemical Degradation of Glucose on Highly Effective Self-Organized TiO2 Nanotube Arrays

The kinetics and mechanisms of photoelectrochemical catalytic degradation of glucose on self-organized TiO2 nanotube arrays (TNAs) were investigated. A thin-layer cell was used to obtain an exhausted reaction condition with which an overall degradation process of glucose could be identified including surface reaction on TNAs and mass transfer from body solution to the diffuse layer. Current-time (Iph-t) and the corresponding differential coefficient profiles were used to analyze the micro-processes of photoelectrochemical catalytic degradation. The initially generated photocurrents on glucose degradation versus glucose concentrations fits well with Langmuir adsorption isotherm, I0ph = 0.00008c0/(1+0.69274c0)+0.00034. This confirmed the adsorption of glucose on TNAs film catalyst was a single molecule layer adsorption, and the photoelectrochemical catalytic degradation reaction kinetics on TNAs surface belonged to a first-order reaction. After the initial quick reaction, three consecutive micro kinetic processes were revealed by the differential coefficient profiles (dIph/dt-t) of the glucose degradation profiles (Iph-t).

摘要研究了自组装TiO2纳米管(TNAs)光电催化降解葡萄糖的动力学和机理.利用薄层反应器进行耗竭反应,研究了TNAs表面催化反应和溶液本体-扩散层传质有关的葡萄糖降解过程.采用电流-时间曲线以及相应的微分曲线分析了光电化学催化降解的微观进程.结果表明,葡萄糖的初始浓度与降解的起始电流强度符合Langmuir吸附等温式I0ph=0.00008c0/(1+0.69274c0)+0.00034,葡萄糖在TNAs薄膜催化剂表面的吸附为单一分子层吸附,其光电催化降解反应符合一级反应动力学,葡萄糖降解反应经历了三个不同的反应过程.

The current-time profile (Iph-t) of photoelectrocatalytic degradation of glucose on self-organized TiO2 nanotube arrays (TNAs) and the related differential coefficient profile (inset of the figure, dIph/dt-t) reveal three distinctive micro-kinetic degradation processes.Figure optionsDownload as PowerPoint slide