催化学报

催化学报 ›› 2019, Vol. 40 ›› Issue (3): 326-334.DOI: 10.1016/S1872-2067(18)63165-1

• 论文 • 上一篇    下一篇

Z-机制WO3(H2O)0.333/Ag3PO4复合材料的制备及其增强光催化活性和稳定性

李真a, 王侠c, 张金锋a, 梁长浩b, 芦露华d, 代凯a   

  1. a 淮北师范大学物理与电子信息学院, 安徽省含能材料重点实验室, 安徽淮北 235000;
    b 中国科学院固体物理研究所, 中国科学院材料物理重点实验室和安徽省纳米材料与技术重点实验室, 安徽合肥 230031;
    c 泊头职业学院机械设计系, 河北沧州 062150;
    d 中国地质大学纳米矿物材料及应用教育部工程研究中心, 湖北武汉 430074
  • 收稿日期:2018-07-31 修回日期:2018-09-15 出版日期:2019-03-18 发布日期:2019-02-22
  • 通讯作者: 代凯, 张金锋
  • 基金资助:

    国家自然科学基金（51572103，51502106）；安徽省杰出青年基金（1808085J14）；安徽省高等学校省级优秀青年人才基金（gxyqZD201751）；安徽省教育厅重点项目（KJ2016SD53）；安徽省创新团队（KJ2015TD003）.

Preparation of Z-scheme WO3(H2O)0.333/Ag3PO4 composites with enhanced photocatalytic activity and durability

Zhen Lia, Xia Wangc, Jinfeng Zhanga, Changhao Liangb, Luhua Lud, Kai Daia   

  1. a School of Physics and Electronic Information, Anhui Key Laboratory of Energetic Materials, Huaibei Normal University, Huaibei 235000, Anhui, China;
    b Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, Anhui, China;
    c Department of Mechanical Engineering and Design, Botou Vocational College, Cangzhou 062150, Hebei, China;
    d Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Wuhan 430074, Hubei, China
  • Received:2018-07-31 Revised:2018-09-15 Online:2019-03-18 Published:2019-02-22
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (51572103 and 51502106), the Distinguished Young Scholar of Anhui Province (1808085J14), the Foundation for Young Talents in College of Anhui Province (gxyqZD2017051), the Key Foundation of Educational Commission of Anhui Province (KJ2016SD53), and the Innovation Team of Design and Application of Advanced Energetic Materials (KJ2015TD003).

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摘要：

Ag3PO4由于具有独特的活性而被广泛应用于光催化领域.然而，由于其光生电子和空穴的快速复合，Ag3PO4的光催化性能在几个循环之后显著下降，光腐蚀限制了它的实际应用.因此，亟需设计一种新型的复合光催化剂来抑制电子空穴对的快速复合.而Z型复合光催化剂可综合不同光催化剂的优点，克服单一光催化剂的缺点.Z方案体系使用两个窄带隙的催化剂取代宽带隙的光催化剂，从而可以捕获更多的光子.并且光催化剂的氧化还原反应分开进行，可以有效地防止电子和空穴的复合，从而大大提高复合光催化剂的性能.
本文通过微波水热法和简单搅拌法成功地制备了Z机制WO3（H2O）0.333/Ag3PO4复合材料.采用X射线衍射、扫描电子显微镜、X射线光电子能谱、N2吸附-解吸等温线、比表面积测定、紫外-可见光谱和光电流曲线等方法对WO3（H2O）0.333/Ag3PO4复合材料进行了表征.通过这些表征，我们确定了所研究的光催化剂物相高度匹配；确定了光催化剂的形貌：确定了复合光催化剂是复合物，而不是简单的混合物；确定了光催化剂中光生电子和空穴的结合、分离效率；研究了光催化剂的吸收边以及带隙.光催化降解测试发现，WO3（H2O）0.333/Ag3PO4复合材料在可见光下表现出优异的催化性能，这主要归因于WO3（H2O）0.333/Ag3PO4的协同作用.其中15% WO3（H2O）0.333/Ag3PO4的光催化活性最高，在4 min内几乎将30 mL 20 mol/L的次甲基蓝完全降解.并且，复合材料的稳定性也得到很大提升.经过5次循环反应后，15% WO3（H2O）0.333/Ag3PO4的降解效率仍可以维持在88.2%.相比之下，纯Ag3PO4的降解效率仅为20.2%.这表明添加WO3（H2O）0.333可以显著提高Ag3PO4的耐光腐蚀性.
最后，我们详细研究了Z-机制机理.在可见光照射下，Ag3PO4和WO3（H2O）0.333的表面产生电子-空穴对.WO3（H2O）0.333的光生电子首先转移到其导带，然后迁移到Ag3PO4的价带中与空穴结合.因此，Ag3PO4的光生电子和空穴被有效分离，光生电子连续转移到Ag3PO4的导带界面.这样，Ag3PO4的导带界面上积累了大量的电子，并且在WO3（H2O）0.333的价带界面中积累了大量的空穴.在空穴的作用下，-OH与h+反应生成·OH，·OH与污染物甲基蓝反应生成CO2和H2O.同时，大量的H+和O2与电子反应，在Ag3PO4的导带界面处产生H2O2.之后，H2O2与电子反应产生·OH，·OH与甲基蓝反应形成CO2和H2O.这样，光生电子和空穴连续分离，大大提高了光催化反应速度，最终催化剂的光催化活性得到极大的提高.

关键词: 光催化, Ag3PO4, WO3(H2O)0.333, 复合材料, Z-机制

Abstract:

Ag3PO4 is widely used in the field of photocatalysis because of its unique activity. However, photocorrosion limits its practical application. Therefore, it is very urgent to find a solution to improve the light corrosion resistance of Ag3PO4. Herein, the Z-scheme WO3(H2O)0.333/Ag3PO4 composites are successfully prepared through microwave hydrothermal and simple stirring. The WO3(H2O)0.333/Ag3PO4 composites are characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and UV-Vis spectroscopy. In the degradation of organic pollutants, WO3(H2O)0.333/Ag3PO4 composites exhibit excellent performance under visible light. This is mainly attributed to the synergy of WO3(H2O)0.333 and Ag3PO4. Especially, the photocatalytic activity of 15% WO3(H2O)0.333/Ag3PO4 is the highest, and the methylene blue can be completely degraded in 4 min. In addition, the stability of the composites is also greatly enhanced. After five cycles of testing, the photocatalytic activity of 15% WO3(H2O)0.333/Ag3PO4 is not obviously decreased. However, the degradation efficiency of Ag3PO4 was only 20.2%. This indicates that adding WO3(H2O)0.333 can significantly improve the photoetching resistance of Ag3PO4. Finally, Z-scheme photocatalytic mechanism is investigated.

Key words: Photocatalysis, Ag3PO4, WO3(H2O)0.333, Composites, Z-scheme