| TiO2/PS/Fe3O4 光催化剂的低温制备及其光催化和磁回收性能 |
| 摘要点击 3970 全文点击 1767 投稿时间：2011-10-05 修订日期：2011-12-13 |
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| 中文关键词 二氧化钛 磁载光催化剂 低温 光催化活性 磁回收 |
| 英文关键词 titanium dioxide magnetic photocatalyst low temperature photocatalytic activity magnetic recovery |
| 作者 | 单位 | E-mail | | 王雪姣 | 兰州交通大学环境与市政工程学院, 寒旱地区水资源综合利用教育部工程研究中心, 兰州 730070 | xiaopihaixuejiao@163.com | | 任学昌 | 兰州交通大学环境与市政工程学院, 寒旱地区水资源综合利用教育部工程研究中心, 兰州 730070 | rxchang1698@hotmail.com | | 念娟妮 | 兰州交通大学环境与市政工程学院, 寒旱地区水资源综合利用教育部工程研究中心, 兰州 730070 | | | 肖举强 | 兰州交通大学环境与市政工程学院, 寒旱地区水资源综合利用教育部工程研究中心, 兰州 730070 | | | 王刚 | 兰州交通大学环境与市政工程学院, 寒旱地区水资源综合利用教育部工程研究中心, 兰州 730070 | | | 常青 | 兰州交通大学环境与市政工程学院, 寒旱地区水资源综合利用教育部工程研究中心, 兰州 730070 | |
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| 中文摘要 |
| 以聚苯乙烯(PS)包覆油酸修饰过的纳米Fe3O4为磁核,在低温(90℃)、中性(pH=7左右)条件下,制备了以PS为惰性隔离层的磁载TiO2光催化剂.用X射线衍射仪(XRD)、透射电子显微镜(TEM)、傅里叶红外分光光度计(FT-IR)、振动样品磁强计(VSM)对催化剂的物相组成、形貌、表面性质、磁学性质进行了表征.以苯酚为模拟污染物,考察了其光催化活性,以自制的磁回收装置,考察其回收特性.结果表明,低温制备的TiO2为锐钛矿结构,平均粒径为2~5 nm,催化剂TiO2/PS/Fe3O4[其中物质的量比为n(TiO2) :n(St) :n(Fe3O4)=60 :2.5 :1]具有结构完整的壳/壳/核结构,TiO2在PS/Fe3O4表面负载牢固; 光催化降解苯酚遵循一级反应动力学方程,TiO2/PS/Fe3O4[n(TiO2) : n(St) :n(Fe3O4)=60 :2.5 :1]的反应速率常数K=0.0258,与纯TiO2的活性接近(K=0.0262); 循环使用5次后,反应速率常数仅降低0.0034.所制催化剂具有较强的磁感应强度,平均回收率可达到92%以上.该低温水解法制备的磁载TiO2光催化剂具有良好的应用前景. |
| 英文摘要 |
| 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℃) 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/Fe3O4 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. |
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