Visible light-driven photocatalytic degradation of rhodamine B over NaBiO3: pathways and mechanism.
Visible light-driven photocatalytic degradation of rhodamine B over NaBiO3: pathways and mechanism.
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DOI：
10.1021/jp905173e
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发表时间：
2009-08
期刊：
影响因子：
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通讯作者：
Kai Yu;Shaogui Yang;Huan He;Cheng Sun;Chenggang Gu;Yongming Ju
中科院分区：
文献类型：
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作者：
Kai Yu;Shaogui Yang;Huan He;Cheng Sun;Chenggang Gu;Yongming Ju
研究了可见光照射下NaBiO_3光催化降解罗丹明B(RhB)。在一定条件下，重组人血红蛋白(20 mg/L)在30min内几乎完全脱色。结果表明，催化剂加热温度对催化剂的光催化活性有显著影响，其中结晶水起重要作用，原始样品比加热后的样品表现出更高的活性。为了研究染料光降解的机理，采用了UV-Vis光谱、高效液相色谱、LC/MS/MS和GC/MS等多种分析方法来监测反应的时间过程。分离鉴定了所有N-脱乙基中间体和几个小分子产物。两个异构体中间体(DR和EER)之间的产率差异被认为与染料分子电子密度的变化有关。在此基础上，提出了NaBiO_3光降解RhB的两种可能途径：生色团裂解和N-脱乙基。然而，染料生色团结构的裂解超过了N-脱乙基。
The photocatalytic degradation of rhodamine B (RhB) over NaBiO3 under visible light irradiation was investigated in this study. RhB (20 mg/L) was almost completely decolorized in 30 min in given conditions. It was found that catalyst heating temperature significantly influenced the photocatalytic activity of the catalyst in which crystal water may played an important role, and the original sample exhibited higher activity than the heated samples did. To scrutinize the mechanistic details of the dye photodegradation, several critical analytical methods including UV-vis spectroscopy, HPLC, LC/MS/MS, and GC/MS were utilized to monitor the temporal course of the reaction. All N-deethylation intermediates and several small molecular products were separated and identified. The yield distinctness between two isomer intermediates (DR and EER) was considered to be correlated with the changes in the electron density of the dye molecule. Then two possible competitive photodegradation pathways of RhB over NaBiO3 were proposed: Chromophore cleavage and N-deethylation. Yet, cleavage of dye chromophore structure predominated over the N-deethylation.