摘要
以五水硝酸铋和钨酸钠为原料水热法合成规整的三维花状直径约2.5—3.5μm的Bi2WO6微球,通过简单原位光还原过程合成了一系列Ag/Bi2WO6复合材料.紫外可见漫反射光谱表明Ag/Bi2WO6相比于纯Bi2WO6微球在可见光区域的光吸收边显著红移.在可见光照射下,对所制备的样品的光催化降解罗丹明B活性进行了评价.结果表明,Ag/Bi2WO6光催化活性随着光还原时间增加,先增加然后降低,光还原时间为20 min合成的Ag/Bi2WO6光催化活性最佳,40 min对罗丹明B的降解率已达到99.2%,反应速率常数为纯Bi2WO6的3.60倍.增强的光催化活性归因于银的引入导致光吸收范围的增加和光生载流子有效分离的协同效应.
Three-dimensional flower-like Bi2WO6 microspheres with the diameter of 2.5—3.5μm were prepared by facile hydrothermal method using bismuth nitrate pentahydrate and sodium tungstate dihydrate as raw materials.A series of Ag/Bi2WO6 were synthesized through a simple and practical photoreduction process with different photoreduction time.The UV-visible diffuse reflectance spectra indicated that Ag/Bi2WO6 was significantly red-shifted compared to pure Bi2WO6 microspheres in the visible light region.The photocatalytic activities of the as-prepared samples were evaluated by the decolorization of rhodamine B under visible light irradiation.The results revealed that the photocatalytic activities of the Ag/Bi2WO6 samples increased first and then decreased with increasing photoreduction time and Ag/Bi2WO6 sample with photoreduction time 20 min exhibited the best photocatalytic activity,the degradation rate of rhodamine B had reached 99.2%under visible light irradiation for 40 min,and the photocatalytic reaction rate constants of Ag/Bi2WO6 was 3.60 times of pure Bi2WO6.The enhanced photocatalytic activity could be attributed to the synergistic effect of increased light absorption range and the effective separation of photogenerated carriers caused by Ag nanoparticles.
作者
王染
黄毅
刘喜梅
余博
WANG Ran;HUANG Yi;LIU Ximei;YU Bo(School of Management,Hunan Institute of Engineering,Xiangtan,411104,China;Hunan Provincial Key Laboratory of Environmental Catalysis and Waste Recycling,Hunan Institute of Engineering,Xiangtan,411104,China)
出处
《环境化学》
CAS
CSCD
北大核心
2020年第3期755-761,共7页
Environmental Chemistry
基金
湖南省教育厅优秀青年基金(19B126)
湖南省自然科学基金(2019JJ40058)
环境催化与废弃物再生化湖南省重点实验室开放基金(2018KF06)资助
关键词
钨酸铋
银
光催化
协同效应
表征
bismuth tungstate
silver
photocatalysis
synergistic effect
characterization
