Bi4Ti3O12/g-C3N4复合光催化剂的制备及其光催化性能研究  

Preparation of BiTiO/g-CN composite photo-catalysts and study on their photocatalytic activity

作　　者：张根 黄自力[1] 葛胜涛 田亮[2] 张海军[2] ZHANG Gen;HUANG Zi-li;GE Sheng-tao;TIAN Liang;ZHANG Hai-jun(Hubei Provincial Key Laboratory for Efficient Utilization and Agglomeration of Metallurgical Mineral Resources,Wuhan University of Science and Technology,Wuhan 430081,China;The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学冶金矿产资源高效利用与造块湖北省重点实验室,湖北武汉430081 [2]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081

出　　处：《现代化工》2020年第8期83-87,92,共6页Modern Chemical Industry

基　　金：国家自然科学基金面上项目(51472184,51872210);湖北省教育厅高等学校优秀中青年科技创新团队计划(T201602);湖北自然科学基金创新群体项目(2017CFA004)。

摘　　要：采用机械混合/热处理的方法制备了具有异质结结构的Bi4Ti3O12/g-C3N4复合光催化剂,利用XRD、SEM及UVVis对所制备的复合光催化剂的结构与形貌进行了表征。结果表明,复合光催化剂中形成了异质结构,其禁带宽度减小,吸收带边红移,可见光吸收增加。以Rh B为目标污染物评价复合光催化剂的活性,考察了不同g-C3N4复合量对光催化剂反应活性的影响。结果表明,异质结型复合光催化剂的光催化活性明显优于单相Bi4Ti3O12;当g-C3N4的质量分数为20%时,其光催化性能最佳(90 min达92.8%),其表观反应常数为单相Bi4Ti3O12的4倍。复合光催化剂光催化活性提高的原因是Bi4Ti3O12与g-C3N4之间形成了异质结,显著降低了光生电子和空穴的复合几率。外加捕获剂的实验结果表明,复合光催化剂的主要活性基团为空穴(h+)与超氧自由基(·O2-)。Bi4Ti3O12/g-C3N4 composite photocatalysts are prepared by a mechanical mixing/heat treatment method.The structure and morphology of as-prepared Bi4Ti3O12/g-C3N4 are characterized by XRD,SEM and UV-Vis.The results indicate that heterojunction structure is formed in Bi4Ti3O12/g-C3N4,thus decreasing the band gap of Bi4 Ti3 O12,redshifting the absorption band edge,and enhancing the absorption of visible light.The photocatalytic activity is evaluated through the degradation of Rh B solution under visible light irradiation and the influences of the amount of g-C3N4 on the reactive activity of the photocatalysts are researched.Compared with the single-phase Bi4Ti3O12,Bi4Ti3O12/g-C3N4 composite photocatalysts with a heterojunction structure exhibits better photocatalytic performance.It is found that Bi4Ti3O12/g-C3N4 photocatalyst with 20%of g-C3 N4 exhibits the best photocatalytic activity,reaching 92.8%in 90 min,and its apparent reaction constant is about 4 times that of single-phase BBi4Ti3O12.Higher photocatalytic activity can be ascribed to the formation of a heterojunction between Bi4Ti3O12/g-C3N4,which markedly suppresses the recombination of photogenerated electron-hole pairs.Analysis on the radical scavengers experiment results confirms that h+and.O2-are the primary reactive species for the photocatalysis process.

关 键 词：BI4TI3O12 g-C3N4 异质结 光催化 

分 类 号：O643.3[理学—物理化学]