催化学报 ›› 2023, Vol. 52: 239-251.DOI: 10.1016/S1872-2067(23)64496-1

• 论文 • 上一篇    下一篇

漂浮型Bi2WO6/C3N4/碳布S型异质结光催化材料用于高效净化水体环境

蔡铭洁a, 刘艳萍a,*(), 董珂欣a, 陈晓波b, 李世杰a,*()   

  1. a浙江海洋大学海洋科学与技术学院, 国家海洋设施养殖工程技术中心, 浙江省海产品健康危害因素关键技术研究重点实验室, 浙江舟山316022, 中国
    b密苏里大学堪萨斯城分校化学系, 美国
  • 收稿日期:2023-06-26 接受日期:2023-07-18 出版日期:2023-09-18 发布日期:2023-09-25
  • 通讯作者: *电子信箱: lishijie@zjou.edu.cn (李世杰),liuyp@zjou.edu.cn (刘艳萍).
  • 基金资助:
    国家自然科学基金(U1809214);国家自然科学基金(51708504);浙江省自然科学基金(LY20E080014);浙江省自然科学基金(TGN23E080003);舟山市科技计划项目(2022C41011)

Floatable S-scheme Bi2WO6/C3N4/carbon fiber cloth composite photocatalyst for efficient water decontamination

Mingjie Caia, Yanping Liua,*(), Kexin Donga, Xiaobo Chenb, Shijie Lia,*()   

  1. aKey Laboratory of Health Risk Factors for Seafood of Zhejiang Province, National Engineering Research Center for Marine Aquaculture, College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan 316022, Zhejiang, China
    bDepartment of Chemistry, University of Missouri-Kansas City, MO 64110, USA
  • Received:2023-06-26 Accepted:2023-07-18 Online:2023-09-18 Published:2023-09-25
  • Contact: *E-mail: lishijie@zjou.edu.cn (S. Li),liuyp@zjou.edu.cn (Y. Liu).
  • Supported by:
    National Natural Science Foundation of China(U1809214);National Natural Science Foundation of China(51708504);Natural Science Foundation of Zhejiang Province(LY20E080014);Natural Science Foundation of Zhejiang Province(TGN23E080003);Science and Technology Project of Zhoushan(2022C41011)

摘要:

近年来, 水污染成为人类生存面临的巨大危机, 如何治理水污染, 特别是如何有效去除水体中的抗生素和重金属存在着很多挑战. 采用先进、绿色且高效的光催化技术可有效去除水污染, 因而受到科研工作者的广泛关注, 但粉末状光催化剂易团聚、难分离回收等问题限制了其工业应用. 近年来, 人们发现将粉末状光催化剂固定在柔性大表面积且电荷传导性能良好的碳布上可以有效克服上述缺点. g-C3N4具有高光还原活性、高稳定性和低成本的优点, 因而在环境净化领域具有突出的应用潜力. 但单一组分的C3N4/碳布仍存在氧化能力弱、光生载流子分离效率低等问题. 将其与高光催化氧化活性且能带位置匹配的Bi2WO6共同构筑具有强内建电场和保留最大氧化还原能力的S型异质结, 是一种有效策略, 有望开发出高效、可回收的可见光光催化体系.

本文以柔性、大的碳布为基底, 通过热聚合-溶剂热法将C3N4和富含氧空位的Bi2WO6原位生长在碳纤维上, 制备出了富含氧空位的S型Bi2WO6/C3N4/CF布状光催化剂, 并用于可见光照射下高效光催化降解抗生素和还原Cr(VI). 宏观图像、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和傅里叶红外光谱(FTIR)等结果表明, 富含氧空位的Bi2WO6和C3N4纳米片均匀地生长在碳纤维上形成了2D/2D/1D分级易回收的布状结构. X射线光电子能谱(XPS)结果表明了Bi2WO6上氧空位、低价氧化态Bi(3-x)+和W(5-x)+的生成. 与C3N4/CF (Bi2WO6/CF)相比, Bi2WO6/C3N4/CF在可见光照射下的光催化降解盐酸四环素和还原六价铬的效率分别提高了0.5 (1.1)倍和30.2 (19.8)倍. 系统实验证明Bi2WO6/C3N4/CF布状光催化剂较好的光催化性能归因于三个方面: (1) 碳纤维编织而成的分级Bi2WO6/C3N4/CF布结构可以暴露丰富的活性位点、促进污染物的富集以及加强界面电荷转移和空间分离; (2) 缺陷工程协同S型光生载流子分离路径促进了电子和空穴的高效分离; (3) 柔性可漂浮的布状结构赋予了其良好的易回收性和可循环利用性. 此外, 该布状光催化剂具有较好的环境普适性和毒性缓释作用, 可以在不同影响因素下保持良好的光催化活性且降解中间产物毒性减弱. XPS结果中电子结合能的变化和功函数分析进一步确认了其S型光生载流子分离路径, 并通过自由基捕获实验和电子自旋共振波谱仪系统研究了光催化反应机理: Bi2WO6/C3N4/CF布状光催化剂通过S型光生载流子分离路径促进了超氧自由基和羟基自由基的生成, 在降解盐酸四环素的过程中空穴和超氧自由基为主要活性物种, 而在还原六价铬过程中电子和超氧自由基为主要活性基团.

综上, 本文采用缺陷工程结合碳布基底的S型异质结构筑策略, 开发出高性能、易回收、稳定的漂浮型光催化体系, 为高效净化水体环境提供了新思路.

关键词: Bi2WO6/C3N4/碳布, 氧空位, S型异质结, 可漂浮光催化剂, 可回收利用, 内部电场

Abstract:

The development of easily recyclable and advanced photosystems is a promising strategy for achieving sustainable water decontamination in industrial applications. In this study, a flexible, floatable, and easily recyclable S-scheme photosystem of oxygen vacancy (OV)-rich Bi2WO6/C3N4/carbon fiber cloth (BWOV/CN/CF) was fabricated via sequential in situ growth of C3N4 and Bi2WO6 with oxygen vacancies on CF cloth. The integrated BWOV/CN/CF photosystem exhibited outstanding photocatalytic decontamination rates for TC (0.0353 min‒1) and Cr(VI) (0.0187 min−1), significantly exceeding CN/CF by 0.5 and 30.2 folds, respectively. This appreciable improvement is derived from the unique hierarchical S-scheme heterostructure with OV, which enables the enhanced capability of BWOV/CN/CF in light use and powerful photocarrier detachment, as well as offering abundant active centers. Significantly, the BWOV/CN/CF cloth shows intriguing industrial application prospects owing to its high anti-interference properties, broad pH applicability, good durability, easy recycling and operation, and extensive adaptability for diverse contaminant purification. Furthermore, the photocatalytic TC decomposition process, by-product biotoxicity, and photocatalysis mechanism were systematically evaluated. The ingenious design of floatable cloth-shaped photosystems offers an effective strategy for environmental purification.

Key words: Bi2WO6/C3N4/carbon cloth, Oxygen vacancy, S-scheme, Floatable photocatalyst, Recyclability, Internal electric field