工业水处理 ›› 2023, Vol. 43 ›› Issue (2): 136-141. doi: 10.19965/j.cnki.iwt.2022-0334

• 试验研究 • 上一篇    下一篇

Ag2O/WO3-SiO2气凝胶的制备及光催化性能研究

陈宝宁1(), 丁春华1,2,3(), 方岩雄1, 刘全兵1   

  1. 1.广东工业大学轻工化工学院,广东 广州 510006
    2.海南大学南海海洋资源利用国家重点实验室,海南 海口 570228
    3.海南省特种玻璃实验室,海南 海口 570228
  • 收稿日期:2022-11-30 出版日期:2023-02-20 发布日期:2023-05-26
  • 通讯作者: 丁春华 E-mail:160154368@qq.com;ding-chh@163.com
  • 作者简介:陈宝宁(1996— ),硕士。电话:13642418413,E-mail:160154368@qq.com
    丁春华,博士,副教授。E-mail:ding-chh@163.com

Preparation and photocatalytic properties of Ag2O/WO3-SiO2 aerogels

Baoning CHEN1(), Chunhua DING1,2,3(), Yanxiong FANG1, Quanbing LIU1   

  1. 1.School of Light Industry and Chemical Engineering,Guangdong University of Technology,Guangzhou 510006,China
    2.State Key Laboratory of Marine Resources Utilization in the South China Sea,Hainan University,Haikou 570228,China
    3.Hainan Special Glass Laboratory,Haikou 570228,China
  • Received:2022-11-30 Online:2023-02-20 Published:2023-05-26
  • Contact: Chunhua DING E-mail:160154368@qq.com;ding-chh@163.com

摘要:

为扩大WO3-SiO2气凝胶的可见光吸收范围,改善其光催化效果,先以溶胶-凝胶法制备了WO3-SiO2气凝胶,再采用浸渍法制备了不同Ag2O负载量的Ag2O/WO3-SiO2复合气凝胶光催化剂。通过扫描电镜(SEM)、X射线衍射分析仪(XRD)、X射线光电子能谱仪(XPS)、紫外-可见光谱仪(UV-vis)、荧光分光光度计(PL)对样品进行了表征分析,并在464 nm波长光源下考察了样品光催化降解亚甲基蓝(MB)的性能。表征结果表明,负载的Ag2O与WO3-SiO2气凝胶中的WO3存在电子转移相互作用,形成了Ag2O/WO3异质结;Ag2O/WO3异质结使催化剂的带隙宽度变窄,有利于光生电子-空穴的激发,同时抑制了电子-空穴对的复合。结合光催化剂降解MB的效果,负载Ag2O形成的Ag2O/WO3异质结增强了Ag2O/WO3-SiO2气凝胶的可见光吸收能力,提高了其光催化性能。其中,Ag2O负载量为0.4%(质量分数)的Ag2O/WO3-SiO2气凝胶具有最佳的催化降解性能,2 h内对MB的降解率达到94.91%,较WO3/SiO2气凝胶提高了58.17%。根据催化剂的能带结构分析,推断了Ag2O/WO3异质结降解MB的可能机理为Ⅱ型异质结机理。

关键词: 氧化钨, 光催化, 气凝胶, 氧化银, 亚甲基蓝, 异质结

Abstract:

In order to expand the visible light absorption range of WO3-SiO2 aerogel and improve its photocatalytic effect,WO3-SiO2 aerogel was fabricated by sol-gel method firstly,and then Ag2O/WO3-SiO2 composite aerogel photocatalysts with different Ag2O loadings were synthesized through impregnation route. The composites were characterized by scanning electron microscopy(SEM),X-ray diffraction analysis(XRD),X-ray photoelectron spectroscopy(XPS),ultraviolet-visible spectroscopy(UV-vis),and fluorescence spectrophotometer(PL). The photocatalytic degradation of methylene blue(MB) by the composite samples were investigated under the light source of 464 nm wavelength. The characterization analyses showed that the loaded Ag2O could interact with WO3 in the WO3-SiO2 aerogel by electron transfer,and the Ag2O/WO3 heterojunction was formed. The heterojunction narrowed the band gap width of the catalyst,which was beneficial to the excitation of photogenerated electrons and holes,while suppressing the recombination of electron-hole pairs. Based on the results of the photocatalytic degradation of MB,the Ag2O/WO3 heterostructure formed by loading Ag2O enhanced the visible light absorption ability and improved the photocatalytic performance. The MB degradation rate of 0.4% Ag2O/WO3-SiO2 aerogel reached 94.91% within 2 h,which was 58.17% higher than that of unmodified WO3-SiO2 aerogel. According to the band structure analysis of the catalyst,the possible mechanism of MB degradation by Ag2O/WO3 aerogel was proposed as Ⅱ-scheme heterostructure.

Key words: tungsten oxide, photocatalysis, aerogel, silver oxide, methylene blue, heterostructure

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