Effect of Fluorination on Photocatalytic Degradation of Rhodamine B over In(OH)ySz: Promotion or Suppression?

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• 作者：Shunwei Hu ; Jia Zhu ; Ling Wu ; Xuxu Wang ; Ping Liu ; Yongfan Zhang ; Zhaohui Li
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：January 20, 2011
• 年：2011
• 卷：115
• 期：2
• 页码：460-467
• 全文大小：503K
• 年卷期：v.115,no.2(January 20, 2011)
• ISSN：1932-7455

文摘

Fluorinated In(OH)_yS_z solid solutions were synthesized via a hydrothermal method. The photocatalytic degradation of rhodamine B (RhB) over the fluorinated In(OH)_yS_z solid solutions revealed that the process of the de-ethylation of RhB was enhanced, while in the meantime, the rate of the mineralization of RhB was suppressed when In(OH)_yS_z was fluorinated. To elucidate the opposite effects of fluorination on the two processes of photocatalytic degradation of RhB (de-ethylation and mineralization) over In(OH)_yS_z, the adsorption of RhB over In(OH)_yS_z with and without fluorination, the active species involved in the de-ethylation and the mineralization of RhB, were investigated, and the electronic structure of fluorinated In(OH)_yS_z was studied. The results indicated that the major active species involved in the de-ethylation and the mineralization of RhB are different, that is, the hole direct oxidation leads to the de-ethylation of RhB, while the major active species responsible for the mineralization of RhB is the O₂^{鈭掆€?/sup> radical. The fluorination on In(OH)_yS_z solid solutions on one hand can enhance the adsorption of RhB on the catalyst surface, leading to a higher rate in the de-ethylation of RhB. On the other hand, fluorination lowers the conduction band of In(OH)_yS_z, which leads to a lower capability of the photogenerated electrons in the reduction of O₂ to give O₂鈭掆€?/sup> radicals. Our results clearly show that the fluorine modifications can have ambilateral effects on the photocatalytic performance of semiconductor photocatalysts depending on the specific photocatalytic reactions.}