高等学校化学学报 ›› 2017, Vol. 38 ›› Issue (12): 2226-2230.doi: 10.7503/cjcu20170371

• 物理化学 • 上一篇    下一篇

g-C3N4@Ag3PO4光催化降解罗丹明B过程的原位光-微热量-荧光光谱研究

万婷1, 李星星1, 黄在银1,2(), 邱江源1, 左晨1, 谭学才1,2   

  1. 1. 广西民族大学化学化工学院,南宁 530006
    2. 广西高校食品药品安全与药物分析化学重点实验室, 南宁 530006
  • 收稿日期:2017-06-12 出版日期:2017-12-10 发布日期:2017-11-23
  • 作者简介:联系人简介: 黄在银, 男, 教授, 主要从事物理化学和材料化学方面的研究. E-mail: huangzaiyin@163.com
  • 基金资助:
    国家自然科学基金(批准号: 21273050, 21573048)和广西民族大学研究生教育创新计划项目(批准号: gxun-chxps201681, gxun-chxzs2016121)资助

In-situ Photocatalytic Process of Rhodamine B over g-C3N4@Ag3PO4 Nanocomposites Based on Photomicrocalorimeter-fluorescence Spectrometry

WAN Ting1, LI Xingxing1, HUANG Zaiyin1,2,*(), QIU Jiangyuan1, ZUO Chen1, TAN Xuecai1,2   

  1. 1. College of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Nanning 530006, China
    2. Guangxi Colleges and Universities Key Laboratory of Food Safety and Pharmaceutical Analytical Chemistry, Guangxi University for Nationalities, Nanning 530006, China
  • Received:2017-06-12 Online:2017-12-10 Published:2017-11-23
  • Contact: HUANG Zaiyin E-mail:huangzaiyin@163.com
  • Supported by:
    Supported by the National Natural Science Foundation of China(Nos.21273050, 21573048) and the Innovation Projects of Postgraduate Education of Guangxi University for Nationalities, China(Nos;gxun-chxps201681, gxun-chxzs2016121)

摘要:

采用光-微热量-荧光光谱联用系统获取了g-C3N4@Ag3PO4光降解罗丹明B(RhB)的原位热/动力学信息和三维荧光光谱信息, 并结合热力学和光谱学结果探究了光催化降解罗丹明B的微观机制. 结果表明, 光催化降解过程主要分为表观吸热、 热平衡以及稳定放热3个阶段. 在g-C3N4@Ag3PO4存在下, 可见光照射10 min后, 罗丹明B的三维荧光特征发射峰强度降低至初始值的7.1%, 罗丹明B的降解脱色率达92.9%, 是相同条件下以纯g-C3N4为催化剂时的2.06倍. 随着光照时间的延长, 光-微热量计显示10 min后以降解及矿化非荧光中间产物为主, 并保持热焓变化率为-(0.226±0.0916) mJ/s稳定放热, 为拟零级反应过程, 并且该阶段为光催化反应的决速步骤.

关键词: 光催化, g-C3N3@Ag3PO3, 光-微热量计, 原位荧光光谱, 热动力学

Abstract:

A photomicrocalorimeter-fluorescence spectrometer was applied to obtain in-situ thermodynamics, kinetics and 3D fluorescence spectra of Rhodamine B photocatalysis over g-C3N4@Ag3PO4 nanocomposites. And its mechanism was investigated by coupling the thermodynamics and its spectroscopic information. Consequently, the whole process underwent an initial endothermic reaction and a subsequent exothermic stage, and finally maintained a stable exothermic platform. The intensity of fluorescence emission peak of Rhodamine B over g-C3N4@Ag3PO4 decreased sharply within the illumination of 10 min, its degradation rate reached 92.9%, which was 2.06 times that over g-C3N4. Subsequently, the photodegradation of the ring and intermediates without fluorescent chromophores were dominated, which maintained a stable exothermic rate of -(0.226±0.0916) mJ/s with a pseudo-zero order process. This process was the rate-determining step. Therefore, Rhodamine B photocatalysis was a pseudo-zero-order process rather than a first order process.

Key words: Photocatalysis, g-C3N3@Ag3PO3, Photomicrocalorimeter, In-situ fluorescence spectrum, Thermokinetics

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