摘要
调节水相悬浮液的pH值,使得酵母菌主体粒子和P25-TiO2客体粒子表面带相反电荷,通过静电自组装法一步合成了草莓结构的TiO2@酵母菌复合光催化剂。FESEM,EDS,FT-IR,XRD,UV-VIS表征了催化剂的物化结构。FESEM结果表明产品具有椭球形态,长度为(3.6±0.50)μm,宽度为(2.4±0.45)μm,分散性好。X射线粉末衍射表明TiO2客体粒子为锐钛矿和金红石矿晶型。紫外-可见光漫反射光谱证实催化剂对紫外光具有光响应。FT-IR分析表明TiO2@酵母草莓结构的形成与酵母细胞表面和TiO2粒子的表面化学官能团有关,其形成机理可概括为静电自组装过程。沉降性能测试表明该复合催化剂具有较好的悬浮性能,这有利于催化剂的分离回收。在光催化降解刚果红染料水溶液中,TiO2@酵母光催化剂表现出了较高的光催化活性。
The opposite zeta-potentials of P25-TiO2 nanoparticles （ guest particles） and yeasts （ host particles） were achieved by adjusting pH of their own aqueous suspensions. Then TiO2@ yeast hybrid micro-spheres with raspberry- like structure were prepared by electrostatic interaction-driven self-assembly. The products obtained were characterized by field emission scanning electron microscopy （FESEM）, Energy Dispersive Spectrometer（ EDS）, X- ray diffraction （ XRD ）, and ultraviolet-visible spectrophotometry （ UV-VIS ）, and fourier transform infrared spectroscopy （FT-IR）, respectively. FESEM indicates that the resulting samples retain ellipsoid shape, with the uniform size [ length （3.6± 0. 50） μm,width （2.4±0. 45 ） μm ] and good dispersity. XRD pattern indicates that the main crystal structure of as-synthesized TiO2 @ yeast microsphere is consisted of anatase and rutile. UV-VIS shows that the samples obtained have a good responding to UV light. FT-IR presents the possible formation mechanisms of TiO2@ yeast hybrid micro-spheres, which can be interpreted by the one-step electrostatic attraction self-assembly. The unique surface traits of the primitive yeast and TiO2 nanoparticles are responsible for the fabrications of TiO2 @ yeast hybrid microspheres. The settling ability of particles indicates that the composite catalysts are good for recycling and reusing. They also exhibit a high photocatalytic activity for the degradation of Congo red dye aqueous solutions.
出处
《化学工程》
CAS
CSCD
北大核心
2012年第10期64-69,共6页
Chemical Engineering(China)
基金
国家自然科学基金资助项目(21176031)
中国博士后特别资助项目(201104615)
陕西省自然科学基金资助项目(2011JM2011)
关键词
草莓结构
静电自组装
TIO2
酵母
光催化
raspberry-like
electrostatic self-assembly
TiO2
yeast
photocatalysis
