锌掺杂OV-β-Bi_(2)O_(3)可见光催化活性的提高:能带结构的调节和电荷分离的促进  

Enhancement of Visible-Light Catalytic Activity for Zn Doped OV-β-Bi_(2)O_(3):Regulation of Electronic Structure and Promotion of Charge Separation

作　　者：赵亚雯 张俊可 冯彩霞[1] 徐佳鹏 杜芮 虎华 周艳梅[1] 刘山虎[1] 刘艳红[3] ZHAO Ya-Wen;ZHANG Jun-Ke;FENG Cai-Xia;XU Jia-Peng;DU Rui;HU Hua;ZHOU Yan-Mei;LIU Shan-Hu;LIU Yan-Hong(Henan Province International Joint Laboratory for Environmental Pollution Control Materials,College of Chemistry and Chemical Engineering,Henan University,Kaifeng,Henan 475004,China;Henan Province Kaifeng Ecological Environment Monitoring Center,Kaifeng,Henan 475003,China;Technical Institute of Physics and Chemistry,Chinese Academy of Science,Beijing 100190,China)

机构地区：[1]河南大学化学化工学院,河南省环境污染控制材料国际联合实验室,开封475004 [2]河南省开封生态环境监测中心,开封475003 [3]中国科学院理化技术研究所,北京100190

出　　处：《无机化学学报》2021年第3期541-554,共14页Chinese Journal of Inorganic Chemistry

基　　金：河南省科技攻关项目(No.19A150020);河南省高校科技创新团队计划(No.19IRTSTHN029);河南省创新创业培训计划(No.S202010475087);开封市科技发展计划项目(No.1808001)资助。

摘　　要：采用溶胶-凝胶-原位碳热还原处理的方法,制备了一种含有氧空位(OV)的新型Zn掺杂β-Bi_(2)O_(3)纳米材料(OV-Zn∶Bi_(2)O_(3)),氧空位的浓度可以通过改变Zn^(2+)的掺杂量进行调节。作为参照,只有氧空位没有Zn^(2+)的新型β-Bi_(2)O_(3)(OV-β-Bi_(2)O_(3))也通过类似的方法制得。通过紫外可见漫反射光谱、X射线光电子能谱、电子顺磁共振、光致发光光谱和光电化学测试,系统研究了氧空位和Zn^(2+)掺杂对OV-Zn∶Bi_(2)O_(3)降解亚甲基蓝(MB)和2,4,6-三氯苯酚(2,4,6-TCP)可见光催化活性的综合影响。结果表明,氧空位的引入不仅可以使光吸收向长波方向拓展,而且可以促进光生载流子的分离。因此,与传统的β-Bi_(2)O_(3)相比,OV-β-Bi_(2)O_(3)对亚甲基蓝(MB)和2,4,6-三氯苯酚(2,4,6-TCP)的降解活性显著增强。对于OV-Zn∶Bi_(2)O_(3)催化剂,Zn^(2+)掺杂可使光催化剂的价带边缘向下移动,增强了光激发空穴的氧化能力,并且适量的锌掺杂也能提高光生载流子的分离效率。因此,OV-Zn∶Bi_(2)O_(3)的可见光活性优于OV-β-Bi_(2)O_(3),而且当Zn与Bi物质的量之比为0.3时,OV-Zn∶Bi_(2)O_(3)-0.3对MB和2,4,6-TCP的降解活性最高。A novel Zn-dopedβ-Bi_(2)O_(3)nanomaterial(OV-Zn:Bi_(2)O_(3))with two crystal defects,oxygen vacancy(OV)and doped Zn^(2+),was prepared via a sol-gel method followed by in-situ carbon thermal reduction treatment.The concentration of OV of OV-Zn:Bi_(2)O_(3)sample can be modulated by regulating the content of doped Zn^(2+).As a reference,the novelβ-Bi_(2)O_(3)having OV but without doped Zn^(2+)(OV-β-Bi_(2)O_(3))was also synthesized via a similar process.The comprehensive effect of OV and doped Zn^(2+)on the visible-light-activity of OV-Zn:Bi_(2)O_(3)for the degradation of methylene blue(MB)and 2,4,6-trichlorophenol(2,4,6-TCP)was investigated by ultraviolet-visible light diffuse reflectance spectra,X-ray photoelectron spectra,electron spin resonance,photoluminescence spectrum and photoelectrochemical measurements.The results show that introduction of OV can not only drastically extend the photoabsorption into longer wavelength region but also promote the separation of photo-generated charge carriers.So,compared to traditionalβ-Bi_(2)O_(3),OV-β-Bi_(2)O_(3)demonstrated highly promoted activity for the degradation of methylene blue(MB)and 2,4,6-trichlorophenol(2,4,6-TCP).For OV-Zn:Bi_(2)O_(3)catalysts,Znic doping can make the valence band edge of catalysts move down and the oxidation ability of photo-excited holes increase.And appropriate amount of zinc doping can also improve the separation efficiency of photogenerated carriers.In contrast to OV-β-Bi_(2)O_(3),the visible light activity of OV-Zn:Bi_(2)O_(3)was further improved and OV-Zn:Bi_(2)O_(3)-0.3 with a molar ratio(nZn/nBi)of 0.3 exhibited the highest activity for the degradation of MB and 2,4,6-TCP.

关 键 词：氧空位 锌离子掺杂 光催化 电荷分离 可见光活性 

分 类 号：O614.241[理学—无机化学] O643.36[理学—化学]