Preparation and photocatalytic property of anatase TiO2 / MnFe2O4core-shell structure nanoparticles
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摘要: 采用柠檬酸盐前驱体技术, 合成了粒径约为20～70 nm 的尖晶石结构MnFe2O4 纳米颗粒, 用聚乙烯亚胺( PEI) 对MnFe2O4 纳米颗粒进行表面处理后, 以异丙醇钛为前驱物, 采用sol2gel 法在纳米MnFe2O4 表面包覆锐钛矿型TiO2 纳米层形成核壳结构。利用透射电子显微镜( TEM) 、X射线衍射仪(XRD) 和振动样品磁强计等测试手段对样品的结构、形貌、粒径以及磁学性能等进行了表征。采用罗丹明B 的光催化降解反应对所制催化剂的活性进行了评价。结果表明, 核壳结构TiO2 / MnFe2O4 复合纳米颗粒的光催化活性随着壳层厚度的增加而增强,当达到一定厚度以后, 其催化活性不随壳层厚度的增加而改变。复合颗粒中TiO2 含量达到30 wt % , 反应时间4 h时, TiO2 / MnFe2O4 磁性光催化剂对罗丹明B 的光降解率达到100 % , 与纯TiO2 纳米粉体的催化活性相当, 且光催化活性稳定, 是一种便于回收、可重复使用的高效光催化剂。
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关键词:
- MnFe2O4 / TiO2 /
- 核壳结构 /
- 复合纳米颗粒 /
- 磁性光催化剂
Abstract: The anatase TiO2 / MnFe2O4 composite nanoparticles with a core-shell structure have been obtained. Thecore MnFe2O4 nanoparticles were synthesized by the co-precipitation method , and the shell TiO2 nanocrystals werederived using the sol-gel technology followed by a heat-t reatment at 450 ℃. The TiO2 / MnFe2O4 samples were characterized by X-ray diff raction (XRD) and t ransmission elect ron microscopy ( TEM) . The TiO2 / MnFe2O4 compositeparticles can be used as a magnetic photocatalyst , which can be fluidized and recovered by an applied magnetic fieldenhancing both the separation and mixing efficiency for recyclable fluids. When the mass f raction of TiO2 is 30 % andthere is enough UV illumination (4 h in our experiment s) , the photodegradation ratio of Rhodamine B by the composite of TiO2 / MnFe2O4 is 100 % , similar to that of the pure TiO2 .-
Key words:
- MnFe2O4 / TiO2 /
- core-shell st ructure /
- composite nanoparticles /
- magnetic photocatalyst
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