Enhanced Photocatalytic Degradation of Methyl Orange by Au/TiO2 Nanoparticles under Neutral and Acidic Solutions
Enhanced Photocatalytic Degradation of Methyl Orange by Au/TiO2 Nanoparticles under Neutral and Acidic Solutions
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DOI：
10.1002/slct.201702664
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发表时间：
2018-02
期刊：
影响因子：
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通讯作者：
M. Tsuji;Kanako Matsuda;Mayu Tanaka;S. Kuboyama;K. Uto;N. Wada;H. Kawazumi;T. Tsuji;H. Ago;J. Hayashi
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文献类型：
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作者：
M. Tsuji;Kanako Matsuda;Mayu Tanaka;S. Kuboyama;K. Uto;N. Wada;H. Kawazumi;T. Tsuji;H. Ago;J. Hayashi
研究了中性和酸性条件下TiO 2和Au/TiO 2光催化剂对橙子（MO）的降解效果。在P25 TiO 2存在下，采用微波-多元醇法制备了Au：Ti原子比为1.5±0.1%：98.5±0.1%的Au/TiO 2光催化剂。TiO 2和Au/TiO 2对MO的初始降解速率在pH 7时分别为0.13和0.22 min− 1，而在pH 2时分别增加到0.96和3.06 min− 1。 这些结果表明，MO降解率提高负载Au纳米粒子的TiO 2在中性和酸性溶液中的1.7和3.2倍，分别。质谱研究使我们得出结论，主要的反应产物是由中性溶液中苯型MO的去甲基化和OH加成形成的，而它们是在酸性溶液中中心N-NH键断裂后，通过MO的喹喔啉形式的开环和羧基化产生的。讨论了Au纳米粒子的电子俘获效应和表面等离子体共振（SPR）效应对提高Au/TiO 2光催化活性的相对重要性。
A comparative study was carried out on the degradation of methyl orange (MO) by TiO2and Au/TiO2photocatalysts in neutral and acidic solutions. Au/TiO2photocatalysts with an Au : Ti atomic ratio of 1.5±0.1% : 98.5±0.1% were prepared by using a microwave‐polyol method in the presence of P25 TiO2. Initial degradation rates of MO by TiO2and Au/TiO2were 0.13 and 0.22 min−1at pH 7, whereas they increased to 0.96 and 3.06 min−1at pH 2, respectively. These results indicate that the MO degradation rates are enhanced by loading Au nanoparticles on TiO2in neutral and acidic solutions by factors of 1.7 and 3.2, respectively. Mass spectroscopic studies lead us to conclude that major reaction products are formed by demethylation and OH addition of benzenoid form of MO in neutral solutions, whereas they are produced through ring opening and carboxylation of quinonoid form of MO after scission of a center N‐NH bond in acidic solutions. The relative importance of electron trapping and surface plasmon resonance (SPR) effects of Au nanoparticles is discussed for the enhancement of photocatalytic activity of Au/TiO2.