2D/2D Ti3C2/Bi4O5Br2 Nanosheet Heterojunction with Enhanced Visible Light Photocatalytic Activity for NO Removal
2D/2D Ti3C2/Bi4O5Br2 Nanosheet Heterojunction with Enhanced Visible Light Photocatalytic Activity for NO Removal
复制标题
具有增强可见光光催化活性的 2D/2D Ti3C2/Bi4O5Br2 纳米片异质结去除 NO
DOI：
10.3866/pku.whxb202005008
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Zhu Gangqiang
中科院分区：
文献类型：
--
作者：
Yang Xiaoqing;Yang Hualin;Lu Huan;Ding Haoxuan;Tong Yanxin;Rao Fei;Zhang Xin;Shen Qian;Gao Jianzhi;Zhu Gangqiang
: This study concentrated on the production of a two-dimensional and two-dimensional (2D/2D) Ti 3 C 2 /Bi 4 O 5 Br 2 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 Ti 3 C 2 , Bi 4 O 5 Br 2 , and Ti 3 C 2 /Bi 4 O 5 Br 2 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 Ti 3 C 2 /Bi 4 O 5 Br 2 was wider than that of Bi 4 O 5 Br 2 . This represents the electrons in the Ti 3 C 2 /Bi 4 O 5 Br 2 nanosheet composites were more likely to be excited. The photocatalytic experiments showed that the 2D/2D Ti 3 C 2 /Bi 4 O 5 Br 2 composite with high photocatalytic activity and stability. The photocatalytic efficiency of pure Bi 4 O 5 Br 2 for the NO removal was 30.5%, while for the 15%Ti 3 C 2 /Bi 4 O 5 Br 2 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%Ti 3 C 2 /Bi 4 O 5 Br 2 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 Ti 3 C 2 /Bi 4 O 5 Br 2 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 ( · O 2 − ) 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 NO 2− and NO 3− . Based on the above experimental results, a possible photocatalytic mechanism was proposed. The electrons in Bi 4 O 5 Br 2 were excited by visible light. They jumped from the valence band (VB) of Bi 4 O 5 Br 2 to the conduction band (CB). Then, the photoelectrons transferred from the CB of Bi 4 O 5 Br 2 to the Ti 3 C 2 surface, which significantly promoted the separation of the electron-hole pairs. Therefore, the photocatalytic efficiency of Ti 3 C 2 /Bi 4 O 5 Br 2 on NO was significantly improved. This study provided an effective method for preparing 2D/2D Ti 3 C 2 /Bi 4 O 5 Br 2 nanocomposites for the photocatalytic degradation of environmental pollutants, which has great potential in solving energy stress and environmental pollution.
