Investigation of the kinetics of a TiO2 photoelectrocatalytic reaction involving charge transfer and recombination through surface states by electrochemical impedance spectroscopy
Investigation of the kinetics of a TiO2 photoelectrocatalytic reaction involving charge transfer and recombination through surface states by electrochemical impedance spectroscopy
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DOI：
10.1021/jp051821z
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发表时间：
2005-08-11
影响因子：
3.3
通讯作者：
Cao, CN
中科院分区：
文献类型：
--
作者：
Leng, WH;Zhang, Z;Cao, CN
建立了TiO2光电催化反应的电化学阻抗谱（EIS）数学模型。利用该模型研究了水杨酸光电催化分解反应动力学。模型模拟结果表明，在EIS响应中出现两个可区分的峰取决于表面态的带电和光强。实验结果表明，类似的现象，理论模拟结果。该模型提供了一种方法来获得的表面态介导的电荷转移和复合的光电化学反应的速率常数。外加电势不仅改变复合速率常数，而且改变电荷转移速率常数。此外，本模型还能较好地解释本文和前人发表的PEC降解反应的EIS实验结果。简要讨论了表面态的相关性。结果表明，电化学阻抗谱是研究有机污染物在TiO2电极上PEC降解动力学的有力工具。
In this paper, the electrochemical impedance spectroscopy (EIS) mathematical model of TiO2 photoelectrocatalytic (PEC) reactions involving charge transfer and recombination through surface states was developed. The model was used to study the kinetics of photoelectrocatalytic decomposition of salicylic acid. The model simulation results show that the appearance of two distinguishable semicircles in the EIS response depends on the charging of surface state and light intensity. The experimental results demonstrated that similar phenomena to the theoretical simulation results. The model provides a way to obtain the rate constants for the photoelectrochemical reactions of surface states mediating charge transfer and recombination. The applied potential changes not only the recombination rate constant but also the charge-transfer rate constant. Moreover, the experimental EIS results here and those previous published on PEC degradation reactions can be explained by the present model satisfactorily. The relevance of surface states was discussed briefly. The results demonstrated that EIS is a powerful tool for studying the kinetics of PEC decomposition of organic pollutants on TiO2 electrodes.