AgBr-Ag-Bi2WO6 nanojunction system: A novel and efficient photocatalyst with double visible-light active components
AgBr-Ag-Bi2WO6 nanojunction system: A novel and efficient photocatalyst with double visible-light active components
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DOI：
10.1016/j.apcata.2009.05.028
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发表时间：
2009-07-01
影响因子：
5.5
通讯作者：
Wong, Po-Keung
中科院分区：
文献类型：
--
作者：
Zhang, Lisha;Wong, Kin-Hang;Wong, Po-Keung
一种基于半导体的光催化剂系统，由两个可见光驱动 (VLD) 组件和一个电子转移系统组成。具有高效光催化降解污染物的巨大潜力。在本文中，我们报道了一种以 Bi2WO6 为基底，通过简单的沉积-沉淀方法构建全固态 AgBr-AgBi2WO6 纳米结的简单策略。两种可见光活性成分（AgBr、Bi2WO6）和电子转移系统（Ag）在空间上固定在该纳米结系统中。由于双可见光活性组分的存在，这种AgBr-Ag-Bi2WO6纳米结体系具有更宽的可见光光响应范围，并且比含有单一可见光活性组分的光催化剂（例如Bi2WO6、Ag-Bi2WO6和AgBr-Ag-TiO2复合材料）表现出更高的光催化活性，用于降解偶氮化合物。 染料、Procion Red MX-5B和无色污染物五氯苯酚，此外，染料的初始浓度和pH值对其光催化活性有很大影响，回收实验证实其在光催化过程中基本稳定。特别是，AgBr-Ag-Bi2WO6纳米结的光催化活性优于含有相同重量的AgBr或Bi2WO6的两种单独光催化剂（AgBr-Ag-TiO2和Bi2WO6）的活性总和，表明AgBr-Ag-Bi2WO6纳米结中两种可见光活性组分之间存在协同效应。根据光催化结果和能带图，提出了AgBr-Ag-Bi2WO6纳米结体系上可能发生的光催化过程；由两种 VLD 组分（AgBr 和 Bi2WO6）的两步激发驱动的矢量电子转移有助于其高光催化活性。因此，这项工作为设计具有多种可见光活性成分的新型高效光催化剂以增强 VLD 光催化活性提供了一些见解。 (C) 2009 Elsevier B.V. 保留所有权利。
A semiconductor-based photocatalyst system, consisting of two visible-light-driven (VLD) components and one electron-transfer system. has a great potential to efficiently photocatalytically degrade pollutants. In this paper, we have reported a simple strategy for constructing an all-solid-state AgBr-AgBi2WO6 nanojunction by a facile deposition-precipitation method with Bi2WO6 as the substrate. Two visible-light active components (AgBr, Bi2WO6) and the electron-transfer system (Ag) are spatially fixed in this nanojunction system. Due to the presence of double visible-light active components, such a AgBr-Ag-Bi2WO6 nanojunction system has the broadened visible-light photo-response range, and it also exhibits higher photocatalytic activity than photocatalysts containing single visible-light active component, such as Bi2WO6, Ag-Bi2WO6 and AgBr-Ag-TiO2 composite, for the degradation of the azo dye, Procion Red MX-5B and colorless pollutant pentachlorophenol, In addition, the initial dye concentration and pH value could greatly affect its photocatalytic activity, and the recycling experiments confirm that it is essentially stable during the photocatalytic process. In particular, the photocatalytic activity of AgBr-Ag-Bi2WO6 nanojunction is superior to the sum of the activities of two individual photocatalysts (AgBr-Ag-TiO2 and Bi2WO6) that contain the same weight of AgBr or Bi2WO6, indicating the presence of a synergic effect between two visible-light active components in AgBr-Ag-Bi2WO6 nanojunction. On the basis of the photocatalytic results and energy band diagram, the photocatalytic process that may have occurred on the AgBr-Ag-Bi2WO6 nanojunction system is proposed; the vectorial electron transfer driven by the two-step excitation of both VLD components (AgBr and Bi2WO6) contributes to its high photocatalytic activity. Therefore, this work provides some insight into the design of novel and efficient photocatalysts with multi-visible-light active components for enhancing VLD photocatalytic activity. (C) 2009 Elsevier B.V. All rights reserved.