Kinetics analysis of interfacial electron-transfer processes in goethite suspensions systems

Ma, Jianzhong and Zhu, Chengzhu and Lu, Jun and Ouyang, Bin and Xie, Qiaoqin and Liu, Haibo and Peng, Shuchuan and Chen, Tianhu (2017) Kinetics analysis of interfacial electron-transfer processes in goethite suspensions systems. Chemosphere, 188. pp. 667-676. ISSN 0045-6535

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Abstract

The photochemical behavior of goethite has been one of the most important topics in the field of environmental science due to it plays a significant role in the removal and transformation process of numerous pollutants. However, the interfacial electron transfer process of goethite is not clear. Using a nanosecond laser flash photolysis spectrometer, we report the transient spectroscopic observations of interfacial electron-transfer reactions in goethite dispersion under UV irradiation. Excitation of goethite generated conduction-band electron (e cb − ) and hole (h + ). The conduction band electron (e cb − ) reacted with an electron acceptor, methylviologen dichloride hydrate (MV 2+ ), forming reduced methylviologen (MV + ) with a second-order rate constant of (2.6 ± 0.3) × 10 9 L mol −1 s −1 . The concentration of MV + was strongly influenced by MV 2+ initial concentration and pH values. The flat band potential of goethite was calculated to be E fb (goethite, pH = 7) = 0.24 V (vs NHE). Oxygen did not react with conduction band electron of goethite. The present study provides a reliable method to investigate the photo-induced interfacial charge transfer of goethite.

Item Type:
Journal Article
Journal or Publication Title:
Chemosphere
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/2300/2307
Subjects:
ID Code:
135581
Deposited By:
Deposited On:
06 Aug 2019 15:25
Refereed?:
Yes
Published?:
Published
Last Modified:
29 Jul 2020 05:48