BiOBr基光催化材料的制备与性能研究
发布时间：2018-08-24 15:28
【摘要】：BiOBr(溴氧化铋)是一种新型可见光响应的半导体光催化材料,因其适中的禁带宽度、开放式层状结构、较高的氧化能力和间接跃迁模式而备受人们关注。如何提高BiOBr的光催化活性,成为现阶段亟需解决的问题。将BiOBr与其他半导体材料复合形成异质结构,能够有效降低BiOBr光生电子-空穴对的复合的几率,从而改善BiOBr的光催化性能。本文选用氯氧化铋(BiOCl)、氧化锌(ZnO)、钒酸铋(BiVO_4)和还原氧化石墨烯(RGO)分别与BiOBr复合并对其光催化性能进行研究。光催化降解实验结果表明:复合后的BiOBr基光催化剂的光反应速率和反应程度在一定程度上均高于纯相BiOBr。具体内容如下:1、BiOCl/BiOBr复合材料的制备与光催化性能研究:以柠檬酸为络合剂,采取水热法制备了花球状BiOCl/BiOBr复合材料。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见漫反射光谱(DRS)和光致发光光谱(PL)等手段对样品的组成与形貌及光吸收性能进行了表征;并以亚甲基蓝(MB)为目标降解物在模拟太阳光下研究了BiOCl/BiOBr的光催化活性。花球状BiOCl/BiOBr复合材料比纯相卤氧化铋材料表现出更高的光催化活性,其中BiOCl0.1Br0.9经60 min光反应后对MB的降解率达80%。2、BiOBr/ZnO复合材料的制备与光催化性能研究:以六水硝酸锌为锌源,在碱性条件下制备出ZnO的前驱物,在无表面活性剂,水热条件下制备出BiOBr/ZnO复合物。通过XRD、SEM、TEM、DRS和PL等手段对产物进行了表征。结果显示出BiOBr和ZnO制备出的p-n异质结有效地减少了光生电子与空穴的复合概率。其中BZ-3(Bi原子与Zn原子的摩尔比为3:1)表现出最好的催化性能。自由基捕获实验结果显示·OH、h+和·O2-等活性粒子参与反应,促进光催化反应。3、BiOBr/BiVO_4复合材料的制备与光催化性能研究:以硝酸铋、溴化钾和钒酸铵为原料,利用水热法制备了BiOBr/BiVO_4催化剂。XRD、SEM和EDS表征表明BiOBr成功与BiVO_4复合。通过亚甲基蓝(MB)的降解评估BiOBr/BiVO_4的光催化性能。0.5BiOBr:0.5BiVO_4复合材料显示出比纯BiVO_4和BiOBr更高的吸附能力,光催化活性最佳。基于这两种半导体的相对带位置提出了可能的光催化机理:复合形成的p-n型异质结促使光生电子与空穴的分离,内建电场也会促进光生载流子的转移。4、BiOBr/RGO复合材料的制备与光催化性能研究:在CTAB辅助水热条件下,将氧化石墨烯(GO)与BiOBr复合成功制备出不同比例的BiOBr/RGO。通过XRD、SEM、FT-IR、DRS、PL等手段表征了催化剂的结构、形貌、元素组成和光学性质等。以亚甲基蓝为模型探究了可见光下BiOBr/RGO的光催化剂活性,对反应机理进行了探讨:石墨烯的沉积显著改变材料的吸光能力,且BiOBr的光生电子易被石墨烯捕获,从而促进了光生电子—空穴对的分离,提高了光催化反应效率。
[Abstract]:Bismuth bromide (BiOBr) is a novel visible light-responsive semiconductor photocatalytic material, which has attracted much attention due to its moderate band gap, open lamellar structure, high oxidation ability and indirect transition mode. How to improve the photocatalytic activity of BiOBr has become an urgent problem at present. Combining BiOBr with other semiconductor materials to form heterostructure can effectively reduce the probability of recombination of BiOBr photogenerated electron-hole pairs and thus improve the photocatalytic performance of BiOBr. In this paper, bismuth chloride bismuth oxide (BiOCl),) zinc oxide (ZnO), (BiVO_4) and reduced graphene oxide (RGO) were used to combine with BiOBr and their photocatalytic properties were studied. The results of photocatalytic degradation experiment showed that the photoreaction rate and reaction degree of the composite BiOBr based photocatalyst were higher than those of pure BiOBr. to some extent. The main contents are as follows: (1) the preparation and photocatalytic properties of BiOCl / BiOBr composites were studied. The spherical BiOCl/BiOBr composites were prepared by hydrothermal method with citric acid as the complexing agent. The composition, morphology and optical absorption properties of the samples were characterized by X-ray diffraction (XRD),) scanning electron microscope (XRD), (SEM), UV-Vis diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). The photocatalytic activity of methylene blue (MB) was studied under simulated sunlight. Compared with pure bismuth halide composite, the flower spherical BiOCl/BiOBr composite showed higher photocatalytic activity. The degradation rate of MB by BiOCl0.1Br0.9 reached 80. 2% after 60 min photoreaction, and the preparation and photocatalytic properties of the composite were studied: zinc nitrate hexahydrate was used as zinc source. The precursor of ZnO was prepared under alkaline condition, and the BiOBr/ZnO complex was prepared under hydrothermal condition without surfactant. The products were characterized by XRD,SEM,TEM,DRS and PL. The results show that p-n heterojunction prepared by BiOBr and ZnO can effectively reduce the recombination probability of photogenerated electrons and holes. BZ-3 (the molar ratio of Bi atom to Zn atom is 3:1) shows the best catalytic performance. The results of free radical capture experiments showed that active particles such as OH,h and O _ 2- participated in the reaction, which promoted the preparation and photocatalytic properties of the photocatalytic reaction .3BiOBr-BiVO4 composite: bismuth nitrate, potassium bromide and ammonium vanadate were used as raw materials. BiOBr/BiVO_4 catalyst was prepared by hydrothermal method. The results of SEM and EDS showed that BiOBr was successfully combined with BiVO_4. The photocatalytic activity of BiOBr/BiVO_4 was evaluated by the degradation of methylene blue (MB). 0.5BiOBr0.5BiVO4 composite showed higher adsorption ability than pure BiVO_4 and BiOBr, and the photocatalytic activity was the best. Based on the relative band position of the two semiconductors, a possible photocatalytic mechanism is proposed: the p-n heterojunction formed by the composite leads to the separation of photogenerated electrons from holes. The built in electric field can also promote the transfer of photogenerated carriers. The preparation and photocatalytic properties of the photogenerated BiOBr-RGO composites: under the CTAB assisted hydrothermal condition, the different ratio of BiOBr/RGO. was successfully prepared by combining graphene oxide (GO) with BiOBr. The structure, morphology, elemental composition and optical properties of the catalyst were characterized by XRD,SEM,FT-IR,DRS,PL. The photocatalytic activity of BiOBr/RGO under visible light was investigated by using methylene blue as a model. The reaction mechanism was discussed: the photoelectron of BiOBr was easily captured by graphene, and the photoabsorption ability of the material was significantly changed by the deposition of graphene. Thus, the separation of photogenerated electron-hole pairs was promoted, and the efficiency of photocatalytic reaction was improved.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36
本文编号：2201244
[Abstract]:Bismuth bromide (BiOBr) is a novel visible light-responsive semiconductor photocatalytic material, which has attracted much attention due to its moderate band gap, open lamellar structure, high oxidation ability and indirect transition mode. How to improve the photocatalytic activity of BiOBr has become an urgent problem at present. Combining BiOBr with other semiconductor materials to form heterostructure can effectively reduce the probability of recombination of BiOBr photogenerated electron-hole pairs and thus improve the photocatalytic performance of BiOBr. In this paper, bismuth chloride bismuth oxide (BiOCl),) zinc oxide (ZnO), (BiVO_4) and reduced graphene oxide (RGO) were used to combine with BiOBr and their photocatalytic properties were studied. The results of photocatalytic degradation experiment showed that the photoreaction rate and reaction degree of the composite BiOBr based photocatalyst were higher than those of pure BiOBr. to some extent. The main contents are as follows: (1) the preparation and photocatalytic properties of BiOCl / BiOBr composites were studied. The spherical BiOCl/BiOBr composites were prepared by hydrothermal method with citric acid as the complexing agent. The composition, morphology and optical absorption properties of the samples were characterized by X-ray diffraction (XRD),) scanning electron microscope (XRD), (SEM), UV-Vis diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). The photocatalytic activity of methylene blue (MB) was studied under simulated sunlight. Compared with pure bismuth halide composite, the flower spherical BiOCl/BiOBr composite showed higher photocatalytic activity. The degradation rate of MB by BiOCl0.1Br0.9 reached 80. 2% after 60 min photoreaction, and the preparation and photocatalytic properties of the composite were studied: zinc nitrate hexahydrate was used as zinc source. The precursor of ZnO was prepared under alkaline condition, and the BiOBr/ZnO complex was prepared under hydrothermal condition without surfactant. The products were characterized by XRD,SEM,TEM,DRS and PL. The results show that p-n heterojunction prepared by BiOBr and ZnO can effectively reduce the recombination probability of photogenerated electrons and holes. BZ-3 (the molar ratio of Bi atom to Zn atom is 3:1) shows the best catalytic performance. The results of free radical capture experiments showed that active particles such as OH,h and O _ 2- participated in the reaction, which promoted the preparation and photocatalytic properties of the photocatalytic reaction .3BiOBr-BiVO4 composite: bismuth nitrate, potassium bromide and ammonium vanadate were used as raw materials. BiOBr/BiVO_4 catalyst was prepared by hydrothermal method. The results of SEM and EDS showed that BiOBr was successfully combined with BiVO_4. The photocatalytic activity of BiOBr/BiVO_4 was evaluated by the degradation of methylene blue (MB). 0.5BiOBr0.5BiVO4 composite showed higher adsorption ability than pure BiVO_4 and BiOBr, and the photocatalytic activity was the best. Based on the relative band position of the two semiconductors, a possible photocatalytic mechanism is proposed: the p-n heterojunction formed by the composite leads to the separation of photogenerated electrons from holes. The built in electric field can also promote the transfer of photogenerated carriers. The preparation and photocatalytic properties of the photogenerated BiOBr-RGO composites: under the CTAB assisted hydrothermal condition, the different ratio of BiOBr/RGO. was successfully prepared by combining graphene oxide (GO) with BiOBr. The structure, morphology, elemental composition and optical properties of the catalyst were characterized by XRD,SEM,FT-IR,DRS,PL. The photocatalytic activity of BiOBr/RGO under visible light was investigated by using methylene blue as a model. The reaction mechanism was discussed: the photoelectron of BiOBr was easily captured by graphene, and the photoabsorption ability of the material was significantly changed by the deposition of graphene. Thus, the separation of photogenerated electron-hole pairs was promoted, and the efficiency of photocatalytic reaction was improved.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36
【参考文献】
相关期刊论文 前10条
1 王浩然;;半导体光催化剂的研究现状与展望[J];精细与专用化学品;2016年12期
2 郭跃萍;吕功煊;;原位合成石墨烯负载的Co-P催化剂及光解水制氢[J];无机化学学报;2016年07期
3 Wanjun Wang;Guocheng Huang;Jimmy C.Yu;Po Keung Wong;;Advances in photocatalytic disinfection of bacteria:Development of photocatalysts and mechanisms[J];Journal of Environmental Sciences;2015年08期
4 崔文权;安伟佳;刘利;胡金山;梁英华;;花状微球BiOBr光催化剂的制备及光催化活性研究[J];功能材料;2013年22期
5 安伟佳;崔文权;刘利;胡金山;梁英华;;卤氧化铋光催化剂的复合改性[J];分子催化;2013年05期
6 林立;黄满红;龙立平;陈亮;陈东辉;;卤氧化铋异质结型可见光光催化剂的新进展[J];材料导报;2013年19期
7 胡蕾;叶芝祥;卢远刚;徐成华;;BiVO_4/TiO_2复合光催化剂的制备及可见光降解腐殖酸[J];分子催化;2013年04期
8 魏龙福;余长林;;石墨烯/半导体复合光催化剂的研究进展[J];有色金属科学与工程;2013年03期
9 刘素芹;戴高鹏;梁英;刘华俊;梁桂杰;;原位碳、氮共掺杂二氧化钛空心球的制备与可见光光催化性能[J];物理化学学报;2013年03期
10 邹照华;何素芳;韩彩芸;张六一;罗永明;;重金属废水处理技术研究进展[J];工业水处理;2010年05期
相关会议论文 前1条
1 常晓峰;袁实;姬广斌;;NaBiO_3/BiOCl复合材料的原位制备及光催化性能研究[A];持久性有机污染物论坛2009暨第四届持久性有机污染物全国学术研讨会论文集[C];2009年
，本文编号：2201244
本文链接：https://www.wllwen.com/kejilunwen/huaxue/2201244.html
教材专著
