物理化学学报2021，Vol.37Issue(10)：150-158,9.DOI:10.3866/PKU.WHXB202005008
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
2D/2D Ti3C2/Bi4O5Br2 Nanosheet Heterojunction with Enhanced Visible Light Photocatalytic Activity for NO Removal
摘要
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,and Ti3C2/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 photocatalyticefficiency 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.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Key words
Ti3C2/Bi4O5Br2/2D/2Dheterojunction/Semiconductor/Photocatalyst/Photocatalytic degradation/NO removal分类
化学化工引用本文复制引用
杨晓庆,朱刚强,杨华琳,卢欢,丁皓璇,童妍心,饶斐,张鑫,申茜,高健智..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[J].物理化学学报,2021,37(10):150-158,9.基金项目
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 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. （21972083,21673118,21972067,11574189,11604196）
