物理化学学报

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高催化活性2D/2D Ti3C2/Bi4O5Br2纳米片异质结的构建及其可见光催化去除NO

杨晓庆1, 杨华琳1, 卢欢2, 丁皓璇3, 童妍心1, 饶斐1, 张鑫1, 申茜4, 高健智1, 朱刚强1   

  1. 1 陕西师范大学物理学与信息技术学院, 西安 710062;
    2 陕西师范大学地理学与旅游学院, 西安 710062;
    3 伯明翰大学物理与天文学院, 伯明翰 B15 2TT, 英国;
    4 南京工业大学先进材料研究院, 柔性电子重点实验室, 南京 211816
  • 收稿日期:2020-05-05 修回日期:2020-06-04 录用日期:2020-06-05 发布日期:2020-06-15
  • 通讯作者: 高健智, 申茜, 卢欢 E-mail:jianzhigao@snnu.edu.cn;iamqshen@njtech.edu.cn;huanlu@snnu.edu.cn
  • 基金资助:
    国家自然科学基金(21972083,21673118,21972067,11574189,11604196),陕西省科技计划项目(2019JM-102,2016KJXX-15),中央高校基本科研业务费专项资金(GK201801005,GK201602006,2018CBLZ002)和陕西师范大学国家级跨学科X物理实验教学示范中心资助

2D/2D Ti3C2/Bi4O5Br2 Nanosheet Heterojunction with Enhanced Visible Light Photocatalytic Activity for NO Removal

Xiaoqing Yang1, Hualin Yang1, Huan Lu2, Haoxuan Ding3, Yanxin Tong1, Fei Rao1, Xin Zhang1, Qian Shen4, Jianzhi Gao1, Gangqiang Zhu1   

  1. 1 School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, P. R. China;
    2 School of Geography and Tourism, Shaanxi Normal University, Xi'an 710062, P. R. China;
    3 School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, United Kingdom;
    4 Key Laboratory of Flexible Electronics, Institute of Advanced Materials, Nanjing Tech University, Nanjing 211816, P. R. China
  • Received:2020-05-05 Revised:2020-06-04 Accepted:2020-06-05 Published:2020-06-15
  • Supported by:
    This project was supported by the National Natural Science Foundation of China (21972083, 21673118, 21972067, 11574189, 11604196), the Science and Technology Program of Shaanxi Province, China (2019JM-102, 2016KJXX-15), the Fundamental Research Funds for the Central Universities, China (GK201801005, GK201602006, 2018CBLZ002), and the National Demonstration Center for Experimental X physical Education of Shaanxi Normal University, China.

摘要: 本研究采用水热法构建出2D/2D Ti3C2/Bi4O5Br2纳米异质结,在可见光下研究了该复合材料对NO的光催化去除能力。实验表明,15% Ti3C2/Bi4O5Br2对NO的光催化去除效率相比纯Bi4O5Br2显著提高:其降解效率达到57.6%,比Bi4O5Br2高27.1%。同时,15% Ti3C2/Bi4O5Br2具有很好的稳定性,经过5次循环催化,其催化率依然接近50.0%。研究发现,反应过程中主要的反应活性物质是e-和·O2-,光氧化产物主要为NO2-和NO3-。分析复合材料的光催化机制,发现光催化活性的提高主要得益于2D/2D Ti3C2/Bi4O5Br2异质结提高了电子与空穴的分离率,从而提高了光催化效率。这项工作提供了一个制备2D/2D纳米复合材料用于光催化降解环境污染物的有效方法,在缓解能源紧张与环境污染方面有巨大应用潜力。

关键词: Ti3C2/Bi4O5Br2, 2D/2D异质结, 半导体, 光催化剂, 光催化降解, NO去除

Abstract: This study concentrated on the production of a two-dimensional and two-dimensional (2D/2D) Ti3C2/Bi4O5Br2 heterojunction with a large interface that applied as one of the novel visible-light-induced photocatalyst via the hydrothermal method. The obtained photocatalysts enhanced the photocatalytic efficiency of the NO removal. The crystal structure and chemical state of the composites were characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that Ti3C2, Bi4O5Br2, andTi3C2/Bi4O5Br2 were successfully synthesized. The experimental results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the prepared samples had a 2D/2D nanosheet structure and large contact area. This structure facilitated the transfer of electrons and holes. The solar light absorptions of the samples were evaluated using the UV-Vis diffuse reflectance spectra (UV-Vis DRS). It was found that the absorption band of Ti3C2/Bi4O5Br2 was wider than that of Bi4O5Br2. This represents the electrons in the Ti3C2/Bi4O5Br2 nanosheet composites were more likely to be excited. The photocatalytic experiments showed that the 2D/2D Ti3C2/Bi4O5Br2 composite with high photocatalytic activity and stability. The photocatalytic efficiency of pure Bi4O5Br2 for the NO removal was 30.5%, while for the 15%Ti3C2/Bi4O5Br2 it was 57.6%. Moreover, the catalytic reaction happened in a short period. The concentration of NO decreased exponentially in the first 5 min, which approximately reached the final value. Furthermore, the stability of 15%Ti3C2/Bi4O5Br2 was favorable:the catalytic rate was approximately 50.0% after five cycles of cyclic catalysis. Finally, the scavenger experiments, electron spin resonance spectroscopy (ESR), transient photocurrent response, and surface photovoltage spectrum (SPS) were applied to analyze the photocatalytic mechanism of the composite. The results indicated that the 2D/2D heterojunction Ti3C2/Bi4O5Br2 improved the separation rate of the electrons and holes, thus enhancing the photocatalytic efficiency. In the photocatalytic reactions, the photogenerated electrons (e-) and superoxide radical (·O2-) were critical active groups that had a significant role in the oxidative removal of NO. The in situ Fourier-transform infrared spectroscopy (in situ FTIR) showed that the photo-oxidation products were mainly NO2- and NO3-. Based on the above experimental results, a possible photocatalytic mechanism was proposed. The electrons in Bi4O5Br2 were excited by visible light. They jumped from the valence band (VB) of Bi4O5Br2 to the conduction band (CB). Then, the photoelectrons transferred from the CB of Bi4O5Br2 to the Ti3C2 surface, which significantly promoted the separation of the electron-hole pairs. Therefore, the photocatalytic efficiency of Ti3C2/Bi4O5Br2 on NO was significantly improved. This study provided an effective method for preparing 2D/2D Ti3C2/Bi4O5Br2 nanocomposites for the photocatalytic degradation of environmental pollutants, which has great potential in solving energy stress and environmental pollution.

Key words: Ti3C2/Bi4O5Br2, 2D/2D heterojunction, Semiconductor, Photocatalyst, Photocatalytic degradation, NO removal

MSC2000: 

  • O643