摘要
以原位化学氧化法在Fe3O4粒子表面负载了聚苯胺(PANI),制得了磁性微球PF(PANI/Fe3O4),并以PF为载体用低温水热法(170℃)在其表面负载了TiO2,最终得到壳/壳/核结构的复合光催化剂TPF[(nTiO2∶nPANI∶nFe3O4)=77∶6∶1].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)对样品物相组成、形貌、表面性质、磁学性质进行了表征和分析.以25 mg·L-1的苯酚为模拟污染物考察其催化活性,以自制的磁回收装置考察磁回收率.结果表明,TiO2粒径在5—8 nm之间,具有锐钛矿和金红石混晶结构;PANI负载在磁核Fe3O4表面可降低磁粒子的团聚作用,使TiO2能更均匀地负载在PANI/Fe3O4表面;复合催化剂TPF具有良好的壳/壳/核结构和超顺磁性,其磁感应强度为4.93 emu·g-1;TPF对苯酚的光催化降解符合伪一级反应动力学,其中纯TiO2、P25和TPF反应速率常数K值分别为0.04381、0.04196、0.02292,TPF循环使用5次和10次之后K值为0.01978、0.01896,活性略有降低,循环使用平均回收率可达92.03%.该法制备的磁载光催化剂TPF具有优良的催化活性和磁回收性能,具有良好的应用前景.
Magnetic photocatalytic composite particles--titania （photoactive shell ）/polyaniline （intermediate layer）/ferroferric oxide （magnetic core） （TiO2/PANI/Fe304, TPF） were prepared by hydrothermal methods. The prepared composite particles were characterized X-ray diffraction （XRD）, transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy （FT-IR）, vibrating sample magnetometer （VSM） and Zetasizer. The photocatalytic activity of the catalysts was evaluated by photocatlytic degradation of phenol （ 25 mg· L- 1 ）, and their magnetic recovery rate was measured by a magnetic recycling equipment. The results indicated that the samples were mix-crystal TiO2 with anatase phase and rutile phase, and its particle size was 5--8 nm. Polyaniline kept the magnetic Fe3 04 dispersed to ensure uniform TiO2 coating on PF during the process of tetrabutyl titanate hydrolysis. The composite photocatalyst TPF （nTiO2： nPANI ： nFe3 04 = 77 ： 6 ： 1 ） exhibited excellent shell/shell/core structure and superparamagnetism, and its magnetic induction was 4.93 emu＇g-I The photocatalytic degradation reation of phenol obeyed pseudo-first order reaction kinetics, and the reaction constants K of the TiO2, P25 and TPF were 0.04381,0. 04196 and 0.02292. After 5 and 10 times repeated use, the reaction constant K of TPF decreased slighty to 0. 01978, 0. 01896. The magnetic recycling rate was 92.03%. Therefore, the magnetic composite photocatalyst had high activity and magnetic reeyclability.
出处
《环境化学》
CAS
CSCD
北大核心
2013年第11期2149-2155,共7页
Environmental Chemistry
基金
国家自然科学基金项目(51068016)资助
国家自然科学基金项目(51268026)资助
中国博士后科学基金第五十批面上项目(2011M501493)资助
关键词
TIO2
PANI
水热法
催化活性
磁回收性
titanium dioxide, polyaniline, hydro-thermal method, magnetic recovery characteriphotocatalytic activity.
