【作者】 朱王勇；

【导师】 吴雪平；

【作者基本信息】 合肥工业大学 ， 化学工艺， 2010， 硕士

【摘要】 本文采用水热法制备了凹凸棒石/碳和凹凸棒石/Fe3O4/碳复合材料,通过在凹凸棒石表面负载碳和Fe3O4改善凹凸棒石亲有机性和磁性能,并考察了制备条件对材料微观结构和吸附性能的影响。主要内容如下：(1)以凹凸棒石、葡萄糖为原料,硫酸亚铁铵为催化剂,水热180℃反应12h,制得凹凸棒石/碳复合材料。葡萄糖分子在水热条件下碳化为直径50nm的碳颗粒,负载在凹凸棒石表面,复合材料中含有-CH有机官能团。随着反应温度的升高、时间的延长和催化剂投入量的增加,凹凸棒石棒束表面的碳层厚度逐渐增加。(2)通过静态吸附实验,凹凸棒石/碳复合材料对苯酚的去除率达到70%,是凹凸棒石原矿(18%)的3倍之多；复合材料对苯酚的吸附动力学符合准二级动力学方程,吸附热力学符合Langmuir等温吸附方程；吸附热力学参数吉布斯自由能变△G0、焓变△H0和熵变△S0均为负值,说明吸附剂对苯酚的吸附是一个自发、放热和熵减小的过程。(3)分别以氨水和NaOH调节pH值制备凹凸棒石/Fe3O4/碳复合材料,产物的磁化率值分别为15562.92×10-8m3/kg和16064.64×10-8m3/kg,用磁分离工序即可把该吸附材料从溶液中快速分离出来；铁的磁性氧化物部分以Fe304的形态负载到了凹凸棒石表面,其含量分别为5.44%和6.14%；碳以无定形的形态负载在凹凸棒石晶体表面；以氨水调节pH值制备的复合材料中含碳量为20.59%,对苯酚的去除率为57%；而以NaOH调节pH值所得复合材料中含碳27.78%,对苯酚的去除率为61%。更多还原

【Abstract】 Palygorskite/carbon and palygorskite/Fe3O4/carbon composites were successfully prepared by hydrothermal method and the adsorption of phenol on the two as-prepared composites were also studied. The work was summarized as followings.(1) Palygorskite, glucose and metal salt as catalyst are utilized as raw materials for synthesizing palygorskite/carbon composite via hydrothermal carbonization at a mild temperature. Glucose is carbonized and then forms nanocarbon with diameter of 50 nm, which grows on the surface of palygorsktie. The composite material contains -CH groups and the thickness of carbon layer can be controlled by reaction time, reaction temperature and catalyst content.(2) Adsorption experiment shows that the removal efficiency of phenol by palygorskite/carbon composite is three times higher than that of unmodified palygorskite. The adsorption kinetics fits the laws of pseudo-second order kinetics. Langmuir adsorption model can be a better description of adsorption behavior of phenol on the palygorskite/ carbon nanocomposites. The thermodynamics parameters including standard Gibb’s free energy changes (△G0), enthalpy (△H0), and entropy changes (△S0) are negative, indicating the adsorption thermodynamics of phenol on nanocomposites is a spontaneous and exothermic process.(3) The palygorskite/Fe3O4/carbon composite is synthesized by hydrothermal method, the pH value is adjusted by ammonia or sodium hydroxide. The results show that the nanocomposite can be subsequently removed from aqueous solution through a simple magnetic procedure. The magnetic iron oxides in the form of Fe3O4 are loaded onto the surface of palygorskite. The content of Fe3O4 and carbon is 5.44% and 20.59%, respectively. The removal efficiency of phenol on composite is 57% when the pH value is adjusted by ammonia. However, the removal rate is changed to 6.14%, 27.78% and 61% respectively while the pH value is adjusted by sodium hydroxide.更多还原