Enhanced and suppressed effects of ionic liquid on the photocatalytic activity of TiO2
Enhanced and suppressed effects of ionic liquid on the photocatalytic activity of TiO2
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DOI：
10.1007/s10450-013-9478-7
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发表时间：
2013-01
期刊：
影响因子：
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通讯作者：
Lifang Qi;Jiaguo Yu;M. Jaroniec
中科院分区：
文献类型：
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作者：
Lifang Qi;Jiaguo Yu;M. Jaroniec
研究了室温离子液体1-丁基-3-甲基咪唑四氟硼酸盐（[Bmim] BF 4）对Degussa P25 TiO 2光催化性能的影响。通过不同的反应性自由基捕获实验，系统地分析了反应机理。结果表明，光生电子是参与光催化降解橙子（MO）的主要活性物种，而·OH自由基和光生空穴在光催化降解罗丹明B（RhB）中起着重要作用。离子液体（IL）的加入对MO的光催化降解有一定的促进作用，这是因为[Bmim]+离子在TiO 2表面的吸附不仅增强了光生电子的捕获和传递，而且促进了带负电MO的吸附。相反，IL抑制了RhB的降解速率，因为TiO 2表面的[Bmim]+不仅阻碍了带正电的RhB进入TiO 2，而且限制了带正电的空穴向TiO 2/溶液界面的扩散。
The effects of a room temperature ionic liquid, 1-butyl-3-methylimidazolium terafluoroborate ([Bmim]BF4), on the photocatalytic performance of Degussa P25 TiO2were investigated. Also, the photocatalysis mechanism was systematically analyzed by conducting different reactive radical trapping experiments. The results showed that photogenerated electrons were the main reactive species involved in the photocatalytic degradation of methyl orange (MO), while •OH radicals and photogenerated holes played an important role in the photocatalytic decomposition of rhodamine B (RhB). The addition of ionic liquid (IL) could slightly enhance the photocatalytic degradation rate of MO because adsorption of [Bmim]+ions on the TiO2surface not only enhanced traping and transfer of photogenerated electrons, but also facilitated adsorption of negatively charged MO. On the contrary, IL suppressed the degradation rate of RhB because [Bmim]+on the TiO2surface not only hindered the access of positively charged RhB to TiO2, but also restricted the diffusion of positively charged holes to the TiO2/solution interface.