波谱学杂志 ›› 2021, Vol. 38 ›› Issue (3): 403-413.doi: 10.11938/cjmr20202815

• 研究论文 • 上一篇    下一篇

原位低场核磁共振弛豫法定量监测光催化Cr(Ⅵ)还原反应

牛星星1,白志杰2,杨翼2,高杨文2,王雪璐1,*(),姚叶锋1,*()   

  1. 1. 上海市磁共振重点实验室, 物理与电子科学学院, 华东师范大学, 上海 200062
    2. 上海纽迈电子科技有限公司, 上海 200333
  • 收稿日期:2020-03-09 出版日期:2021-09-05 发布日期:2020-05-06
  • 通讯作者: 王雪璐,姚叶锋 E-mail:xlwang@phy.ecnu.edu.cn;yfyao@phy.ecnu.edu.cn
  • 基金资助:
    国家自然科学基金资助项目(21603073)

A Quantitative Study of Photocatalytic Reduction of Cr(Ⅵ) by Operando Low-Field NMR Relaxometry

Xing-xing NIU1,Zhi-jie BAI2,Yi YANG2,Yang-wen GAO2,Xue-lu WANG1,*(),Ye-feng YAO1,*()   

  1. 1. Shanghai Key Laboratory of Magnetic Resonance, College of Physics and Electronic Science, East China Normal University, Shanghai 200062, China
    2. Shanghai Niumag Electronic Technology Co., Ltd., Shanghai 200333, China
  • Received:2020-03-09 Online:2021-09-05 Published:2020-05-06
  • Contact: Xue-lu WANG,Ye-feng YAO E-mail:xlwang@phy.ecnu.edu.cn;yfyao@phy.ecnu.edu.cn

摘要:

本文利用原位低场核磁共振(LF-NMR)技术在真实固液反应环境中对光催化还原Cr(Ⅵ)反应进行了定量研究,并对Ag纳米颗粒负载量不同的Ag担载石墨相氮化碳复合光催化剂(Ag/g-C3N4)在可见光照射下催化Cr(Ⅵ)还原为Cr(Ⅲ)的性能进行了研究.研究发现,Ag纳米颗粒负载(负载量分别为1 wt.%、2 wt.%、5 wt.%和10 wt.%)可以有效提高g-C3N4的光催化性能;且负载量为5 wt.%时光催化性能最优,为无Ag负载的g-C3N4的4倍.此外,本文还通过横向弛豫时间(T2)定量分析了反应体系中顺磁性Cr(Ⅲ)离子的浓度,证实了采用LF-NMR弛豫法评价光催化Cr(Ⅵ)还原反应性能的可行性.

关键词: 原位低场核磁共振, g-C3N4, Ag负载, 光催化, Cr(Ⅵ)还原, 横向弛豫时间(T2)

Abstract:

In this work, operando low-field nuclear magnetic resonance (LF-NMR) technology was used to quantitatively study the photocatalytic reduction of Cr(Ⅵ) in a real solid-liquid reaction environment. The performance of Ag/g-C3N4 photocatalysts with different loadings of Ag for the photocatalytic reduction of aqueous Cr(Ⅵ) to Cr(Ⅲ) under visible-light irradiation was systematically investigated. The results showed that the addition of Ag cocatalysts (Ag loading amount: 1 wt.%, 2 wt.%, 5 wt.%, and 10 wt.%) significantly enhanced the photocatalytic performance of g-C3N4 photocatalysts, while the optimal content of Ag loading was 5 wt.%, which was greater than that of pristine g-C3N4 by a factor of 4.0. Furthermore, we carried out a quantitative analysis on the concentration of paramagnetic Cr(Ⅲ) ions in solution by using the transverse relaxation time (T2) values, and proved the viability of employing operando LF-NMR relaxometry for monitoring the photocatalytic Cr(Ⅵ) reduction performance.

Key words: operando LF-NMR, g-C3N4, Ag loading, photocatalytic, Cr(Ⅵ) reduction, transverse relaxation time (T2)

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