| BiOCl-(NH4)3PW12O40复合光催化剂制备及其光催化降解污染物机制 |
| 摘要点击 2198 全文点击 811 投稿时间：2018-08-29 修订日期：2018-09-19 |
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| 中文关键词 BiOCl-NH4PTA 复合光催化剂 甲基橙 光生电子受体 电子空穴分离效率 |
| 英文关键词 BiOCl-NH4PTA composite photocatalyst methyl orange photoelectrons acceptor separation efficiency of electron-hole pairs |
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| 中文摘要 |
| 光生电子和空穴的分离效率是影响光催化性能的重要因素.氯氧铋是典型的层状纳米光催化剂，却因光生电子和空穴的快速复合所表现出的低量子效率而受到使用限制.本文通过两步的水热法合成了BiOCl-（NH4）3PW12O40复合光催化剂.以甲基橙（MO）为模拟污染物进行光催化活性测试.结果表明，在氙灯模拟的太阳光照射下，Bi与W的原子比为1 ∶1时，其催化效果最佳.通过自由基猝灭实验对催化剂光降解MO的催化机制进行了研究，发现BiOCl是由空穴，羟基自由基和超氧自由基共同作用来对MO进行降解；而复合催化剂则主要以羟基自由基和超氧自由基为活性物种来降解MO.通过对反应前后的催化剂进行XPS分析，证明了磷钨酸铵可以接收BiOCl产生的光生电子.通过光电流测试，表明复合光催化剂的光生电子的转移和分离效率有了较大的提高，从而提高了光催化活性. |
| 英文摘要 |
| The separation efficiency of photogenerated electrons and holes is the key to photocatalytic performance. Layered BiOCl is a kind of newly exploited efficient photocatalyst, but its wide-spread practical application is hindered by the rapid recombination of photogenerated electron-hole pairs and low quantum efficiency. In this study, we prepared a composite photocatalyst via a hydrothermal method in which (NH4)3PW12O40 (NH4PTA) is the acceptor of photoelectrons from BiOCl. The photocatalytic performance of variants of BiOCl-NH4PTA was evaluated by the removal efficiency of methyl orange (MO). The experimental results showed that the BiOCl-NH4PTA[n (Bi):n (W)=1:1] had the best photocatalytic activity under the irradiation of sunlight simulated by xenon light. The photocatalytic mechanism was investigated using the reactive species trapping experiments. It was found that MO could be photodegraded by,·OH, and holes over BiOCl. Differently, and·OH were the dominant reactive species for the reactions over the composite photocatalyst. It was proved that NH4PTA was the acceptor of photoelectrons by the XPS on the photocatalyst before and after reaction. The photocurrent test verified the superior photocatalysis of BiOCl-NH4PTA which was attributed to the efficient separation of electron-hole pairs. |
