【作者】 白洁；

【导师】 苏碧桃；

【作者基本信息】 西北师范大学 ， 物理化学， 2007， 硕士

【摘要】 本论文通过对TiO₂进行改性,成功合成了两种复合型催化剂:掺杂型光催化剂和核壳型磁载光催化剂。以亚甲基蓝溶液的脱色研究了复合催化剂的催化性能,探讨了热处理条件和复合物中TiO₂的含量对催化性能的影响,并运用TEM、XRD、UV-Vis等测试技术对复合催化剂的结构进行了表征。本论文主要有以下两个方面组成:1.用溶胶-凝胶法制备了一系列不同Fe³⁺掺杂量的纳米TiO₂光催化剂。结果表明,在所研究的掺杂范围内,该纳米粒子的粒径随Fe³⁺掺杂量的增加呈减小趋势;Fe³⁺的掺入不仅可以控制TiO₂锐钛矿向金红石的转变,而且可以使该纳米微粒对光的吸收向可见区拓展;Fe³⁺的适量掺入,可以显著提高纳米TiO₂在自然光条件下的催化活性。2.采用共沉淀法制备纳米级磁基体（Fe2O₃和NiFe2O₄）,以溶胶-凝胶法制得易于固液分离回收的磁载纳米光催化剂TiO₂/Fe₂O₃和TiO₂/NiFe₂O₄,且研究了催化剂对亚甲基蓝溶液的降解能力,并探讨了焙烧温度及核与壳的配比对催化剂活性的影响。结果表明:本法成功的实现了TiO₂作为壳层对磁性核的包裹,样品为核壳结构。磁核的引入有利于催化剂的吸收光波长范围加宽,并已进入可见光区,且吸收强度也增大。两种磁性催化剂的最佳焙烧温度均为600℃;而最佳配比却有所不同,催化剂TiO₂/Fe₂O₃在配比为20:1时显示出最高的催化活性,催化剂TiO₂/NiFe₂O₄的最佳配比为40:1,磁性催化剂可在8h内对亚甲基蓝的脱色降解率可达到90%左右,最后探讨了导致此类催化剂活性不高的影响因素。更多还原

【Abstract】 In this thesis,two novel composites of TiO₂:doping catalyst and magnetic photocatalyst were successfully designed and prepared with altering property to TiO₂,Their catalytic activities were evaluated by measuring the decolorization efficiency of MB in aqueous solution.In addition,the effects of calcination temperature and TiO₂ content on photocatalytic activity were investigated. These composites were also characterized using TEM、XRD and UV-Vis techniques.This thesis mainly consists of two major aspects.1.Fe³⁺-doped TiO₂ composite nanoparticles with different doping amount（X:0.00～3.00%） were successfully synthesized using sol-gel method and characterized.The influence of amounts of Fe³⁺-doped on photocatalytic activities was investigated under visible light irradiation.The results showed that the size of Fe³⁺/TiO₂ particles decreased with the increasing of the amount of Fe³⁺and their absorption spectra were broadened and absorption intensities were also increased.Doping Fe³⁺ could control the conversion of TiO₂ from anatase to rutile.The doping amount of Fe³⁺remarkably affected the activity of catalyst and the optimum efficiency occurred at 0.3%.The appropriate doping Fe³⁺could markly increase the catalytic activity of TiO₂ under visible light irradiation.2.Nano-magnetite matrix Fe₂O₃ and NiFe₂O₄ were prepared chemical co-precipitation. TiO₂/Fe₂O₃ and TiO₂/NiFe₂O₄ had been successfully prepared by sol-gel method.The photocatalytic activity of these catalysts was tested with MB as decomposition substance.In addition,the effects of calcination and TiO₂ content on photocatalytic activity were investigated.The results showed that the sample was core-shell structure and could absorb the light of ultraviolet to visible.The optimal calcinations temperature was at 600℃;In addition,with the proper TiO₂ content,TiO₂/Fe₂O₃（20:1） and TiO₂/NiFe₂O₄（40:1）composites presented the efficiency activity which the MB was depolarization efficiency at 90%with 8h.And at last the facts due to the low activity was been discussed.更多还原