催化学报

催化学报 ›› 2018, Vol. 39 ›› Issue (9): 1470-1483.DOI: 10.1016/S1872-2067(18)63111-0

• 论文 • 上一篇    下一篇

利用AgVO3改性MoS2增强活性氧产生及其光催化性能的提高

秦莹莹a, 李红a, 卢健c, 闫永胜c, 逯子扬e, 刘馨琳b   

  1. a 江苏大学流体机械工程与技术研究中心, 江苏镇江 212013;
    b 江苏大学能源与动力工程学院, 江苏镇江 212013;
    c 江苏大学绿色化学与化工技术研究院, 江苏镇江 212013;
    d 江苏大学环境与安全工程学院, 江苏镇江 212013
  • 收稿日期:2018-02-22 修回日期:2018-05-20 出版日期:2018-09-18 发布日期:2018-07-19
  • 通讯作者: 刘馨琳
  • 基金资助:

    国家自然科学基金（21706104）；江苏省自然科学基金（BK20150484）；中国博士后科学基金（2015M570416）；江苏大学高级人才基金（14JDG148）.

Enhanced photocatalytic performance of MoS2 modified by AgVO3 from improved generation of reactive oxygen species

Yingying Qina, Hong Lia, Jian Luc, Yongsheng Yanc, Ziyang Lue, Xinlin Liub   

  1. a Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, Jiangsu, China;
    b School of Energy and Power Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, China;
    c Institute of Green Chemistry and Chemical Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, China;
    d School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, China
  • Received:2018-02-22 Revised:2018-05-20 Online:2018-09-18 Published:2018-07-19
  • Contact: 10.1016/S1872-2067(18)63111-0
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21706104), the Natural Science Foundation of Jiangsu Province (BK20150484), the China Postdoctoral Science Foundation (2015M570416), and the financial support of the Research Foundation of Jiangsu University, China (14JDG148).

PDF

1082

摘要：

随着全球工业化进程的发展，环境污染问题日益严重，已经成为21世纪影响人类生存与发展的重要问题.光催化氧化技术被认为是解决环境问题最有应用前景的技术之一，已经成为环境领域的研究热点.众所周知，二硫化钼（MoS2）可以被可见光激发产生电子-空穴对，但是由于其氧化还原电势并不高，抑制了氧分子活化的量子效率，且激发后的光生载流子容易复合，导致光催化效率不高.因此，迫切需要对MoS2光催化材料进行修饰与改性，采用提高光催化过程中活性氧（ROSs）的量来提高其光催化活性.银钒氧化物（AgVO3，Ag2V4O11，Ag3VO4和Ag4V2O7等）因其在锂电池、传感器和光催化剂领域的应用而引起了人们的关注.其中，AgVO3具有较窄的带隙和高度分散的价带，具有潜在的应用价值.
本文采用水热法成功制备了AgVO3/MoS2复合光催化剂，并采用X射线粉末衍射、扫描电子显微、透射电子显微镜和紫外-可见漫反射光谱等表征技术研究了所制光催化剂的物相结构、样品形貌和光学性能.以四环素为研究对象，将其应用于AgVO3/MoS2复合光催化剂的降解实验.结果表明，随着AgVO3质量比从1.0 wt%增加到3.0 wt%，所得催化剂的光催化活性不断提高；当进一步增加AgVO3的质量时，复合催化剂的活性逐渐降低.这是由于过多的AgVO3的引入导致在光催化剂表面形成电子-空穴对复合中心，增加了载流子复合几率.因此，AgVO3/MoS2复合光催化剂中AgVO3的最佳质量比为3.0 wt%，其降解速率常数为0.0087min-1，分别是MoS2（0.00509min-1）和AgVO3（0.00495min-1）的1.71和1.76倍.由于AgVO3改性后的MoS2具有优异的光催化性能，能促进O2的吸附/活化，加速MoS2表面生成H2O2的双电子氧还原反应，从而产生更多的ROSs.利用电子自旋共振光谱、POPHA荧光检测和自由基捕获实验相结合的方法来阐明ROSs的形成机理.同时，ROSs的产生会加速消耗AgOV3导带上的电子，为降解污染物留下更多的空穴.本文为表面催化工程促进ROSs生成的合理设计提供了新的思路，有望在环境治理中得到实际应用.

关键词: 活性氧物种, AgVO3/MoS2, 光催化剂, 可见光, 有机污染物

Abstract:

In this work, an efficient AgVO3/MoS2 composite photocatalyst was successfully synthesized via a hydrothermal method. The photocatalytic activity of the as-prepared photocatalyst was evaluated by using it for assessing the degradation of different organic pollutants under visible-light irradiation. The composite 3%-AgVO3/MoS2 catalyst demonstrated a significantly enhanced photocatalytic activity compared to the pure compounds (AgVO3 and MoS2). The reason behind the excellent photocatalytic performance was the modification of MoS2 by AgVO3 to facilitate O2 adsorption/activation. In addition, the composite catalyst facilitates the two-electron oxygen reduction reaction whereby H2O2 is generated on the surface of MoS2 to produce additional reactive oxygen species (ROSs). ESR coupled with the POPHA fluorescence detection method and a free radical capture experiment were used to elucidate the mechanism of formation of the ROSs, including ·OH, ·O2- and H2O2. Furthermore, the generation of additional ROSs could accelerate electron consumption, leaving behind more holes for the oxidation of organic pollutants. A possible photocatalytic mechanism of the composite is also discussed.

Key words: Reactive oxygen specie, AgVO3/MoS2, Photocatalyst, Visible light, Organic pollutant