【作者】 高薇；

【导师】 陈天虎；

【作者基本信息】 合肥工业大学 ， 环境工程， 2008， 硕士

【摘要】 本论文用硫酸亚铁-硝酸钾氧化法在凹凸棒石悬浮液中即时合成四氧化三铁制备出凹凸棒石-Fe₃O₄复合吸附剂,通过XRD、TEM、MS和FT—IR对复合吸附剂进行表征。以亚甲基蓝为处理对象,研究了煅烧温度对吸附剂吸附效果的影响,研究了磁性凹凸棒石吸附水中亚甲基蓝的吸附动力学、吸附等温线、pH的影响及吸附剂的重复使用性能。用醇盐水解法在凹凸棒石/磁性铁氧化物表面负载TiO₂,制备凹凸棒石/磁性铁氧化物/TiO₂复合光催化剂,通过XRD、TEM、UV-Vis、MS和FT—IR对复合光催化剂进行表征。以甲基橙为处理对象,研究了煅烧温度对光催化剂的吸附、光催化活性的影响,光催化剂投加量、TiO₂不同负载量对光催化性能的影响,复合光催化剂中各物相对光催化性能的影响以及复合光催化剂的重复使用情况。研究结果表明:（1）在制备凹凸棒石负载Fe₃O₄复合材料的过程中,凹凸棒石投加量和凹凸棒石煅烧温度对复合材料的物相组成、形貌特征及磁学性质具有明显的影响。随着凹凸棒石的投加量增加纳米Fe₃O₄颗粒变细、粒径分布更均匀。当凹凸棒石煅烧温度超过300℃以后,由于凹凸棒石表面性质的改变,抑制了Fe₃O₄结晶。（2）制得的复合吸附剂经600℃煅烧吸附效果最好,而且具有很高的磁化率,最适合做磁性吸附剂。复合吸附剂中磁性铁的存在对凹凸棒石的最大吸附量几乎没有影响,但凹凸棒石的吸附速率变慢。复合吸附剂对亚甲基蓝的吸附,随着pH升高,吸附效果变好。磁性凹凸棒石吸附剂适合重复使用,从试验数据看:重复使用6次,仍具有很高的磁化率和吸附效果。（3）凹凸棒石的存在可以控制TiO₂的成核和生长,使得在凹凸棒石表面生成的二氧化钛是纳米尺度的,粒径均匀的,分散性好的颗粒。制得的复合光催化剂在未煅烧情况下的光催化效果最好,磁化率也很高,适合做磁回收光催化剂。随着煅烧温度的升高,复合光催化剂中TiO₂的粒径变大,光催化效果变差。制备的复合光催化剂的光催化效果好于一般分析纯TiO₂的光催化效果。更多还原

【Abstract】 In this research,palygorskite and magnetite composite material was prepared in the system of ferrous sulfate and potassium nitrate with characterization of XRD,TEM, FT—IR and MS.To deal with the methylene blue,It is studied that effect of calcination temperature for absorptive activities of composite absorbent,adsorption dynamics and adsorption isotherm of adsorb methylene blue by Adsorbent,effect of pH and reuse of absorbent.Palygorskite/ magnetic iron oxide/ TiO₂ composite photocatalyst was prepared by hydrolyze Tetrabutyl titanate to load TiO₂ in palygorskite/magnetic iron oxide surface.The composite photocatalyst were characterized by XRD,TEM,UV-Vis,MS,FT-IR.To deal with the methyl orange,It is studied that effect of calcination temperature for absorptive and photocatalytic activities of composite photocatalyst,different photocatalyst dosage and different TiO₂ loadings for photocatalytic efficiency,the phase in composite photocatalyst for photocatalytic efficiency and reuse composite photocatalyst for photocatalytic efficiency.The conclusions are as follows:（1）Load Fe3O4 in surface of palygorskite,the amount of palygorskite adding in the system effect on size,distribution on the surface of palygorskite and magnetic properties of magnetite.As the increase of palygorskite adding, size of magnetite decreases and grain distribution of Fe₃O₄ is more uniformity.While calcined temperature is higher than 300℃,no magnetite crystal is formed in system.（2）The absorption of composite adsorbent calcined at 600℃is the best,with very high susceptibility,which is the most suitable for magnetic absorbent.Magnetic iron in composite adsorbent has almost no impact on the largest adsorption of palygorskite,but slow down the absorption rate of palygorskite.Composite adsorbent for the absorption of methylene blue,with the pH increased absorption effect of improving.Magnetic palygorskite adsorbent is suitable for reuse,we can see that from the test:which reused for six times,still has a very high susceptibility and the absorption effect.（3）The presence of palygorskite can control the nucleation and growth of TiO₂,makes TiO₂ grows on the surface of palygorskite is nanoscale,uniformity,good dispersion of particles. Photocatalytic activities of uncalcined composite photocatalyst is the best,with high susceptibility,which is the most suitable for magnetic photocatalyst.With the increase of calcination temperature,size of TiO₂ in the composite photocatalyst get larger, photocatalytic efficiency get lower.Photocatalytic efficiency of composite photocatalyst is better than the general analyze purely TiO₂.更多还原