Wang Xue-jiao, Ren Xue-chang, Nian Juan-ni, Xiao Ju-qian, Wang Gang, Chang Qing
Engineering Research Center for Cold and Arid Regions Water Resource Comperehensive Utilization of the Ministry of Education, School of Environmental & Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China.
Huan Jing Ke Xue. 2012 Aug;33(8):2752-8.
This study reports the fabrication of magnetically responsive titania catalyst, which consisted of a magnetic core surrounded by a titania shell. The magnetic core (oleic acid-modified Fe3O4 nanoparticles) was modified with polystyrene as inert isolating layer. The magnetic photocatalyst was prepared at low temperature (90 degrees C) and a neutral pH (about 7). The phase composition, morphology, surface properties and magnetic properties of the composite particles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier infrared photometer (FT-IR) and vibrating sample magnetometer (VSM). The photocatalytic activity of the samples were determined by degradation of phenol and their recovery characteristics were determined by a self-regulating magnetic recycling equipment. The results illustrated that the mean diameter of anatase titanium dioxide synthesized at low temperature was 2-5 nm, the catalyst TiO2/PS/Fe3O4 [the molar ratio of the magnetic photocatalyst was n(TiO2): n(St): n(Fe3O4) = 60:2.5:1] had the structural integrity of shell/shell/core, and titanium dioxide was loaded firmly on the PS/FeO4 surface. The photocatalytic degradation of phenol followed first-order reaction kinetics and the reaction rate constant K of the TiO2/PS/Fe3O4 [n(TiO2): n(St): n (Fe3O4) = 60:2.5:1] was 0.0258, which was close to that of pure TiO2 (K = 0.0262). After 5 times recycling, the K value reduced only by 0.0034. The catalyst had a strong magnetic induction, and the average recovery rate reached 92%. The magnetic TiO2 photocatalyst prepared by this low-temperature hydrolysis method has a good application prospect.
本研究报道了磁性响应二氧化钛催化剂的制备，该催化剂由被二氧化钛壳层包围的磁性核组成。磁性核（油酸改性的Fe3O4纳米颗粒）用聚苯乙烯作为惰性隔离层进行了改性。磁性光催化剂在低温（90℃）和中性pH（约7）条件下制备。通过X射线衍射（XRD）、透射电子显微镜（TEM）、傅里叶红外光度计（FT-IR）和振动样品磁强计（VSM）对复合颗粒的相组成、形态、表面性质和磁性进行了表征。通过苯酚降解测定样品的光催化活性，并通过自调节磁回收设备测定其回收特性。结果表明，低温合成的锐钛矿型二氧化钛平均粒径为2-5nm，催化剂TiO2/PS/Fe3O4[磁性光催化剂的摩尔比为n(TiO2):n(St):n(Fe3O4)=60:2.5:1]具有壳/壳/核的结构完整性，二氧化钛牢固地负载在PS/FeO4表面。苯酚的光催化降解遵循一级反应动力学，TiO2/PS/Fe3O4[n(TiO2):n(St):n(Fe3O4)=60:2.5:
