磷酸盐系磁性复合核壳材料的可控制备及染料吸附特性的研究

Water pollution by dyes is becoming more and more serious which requires immediate response. Recently apatites have demonstrated excellent performance in dye absorption in aqueous solutions. In order to meet the requirements for practical application, further investigations on their fast and effective recycle abilities are still needed. In this work, we are going to design and develop a series of apatites on sub-micron level Fe3O4 inner core which combine the fast magnetic separation and excellent dye absorption performance. Through systematic investigation on the structure of the materials, the adsortpion kinetics and the adsorption mechanism,the influence of the structure and composition on the adsorption performance will be discussed. And the adsorption properties for different dyes will be studied systemly to achieve the high adsorption selectivity from complicated aqueous solutions. Depending on studies of the recycle and reusage process after adsorption, a practical route for dye absorption and reuse from aqueous solutions will be established. The accomplishment of this project will be helpful to promote the developments of novel inorganic composites with multi functions and high performance on dye absorption, will be helpful to understand the interaction between dye and composite absorbents, and will be helpful to promote the effective control of dye pollution in aqueous solutions.

水体中染料污染日益严重，已成为亟待解决的环境问题。磷酸盐系材料在染料污水处理研究中已初步展示出良好的吸附特性，但吸附后材料的快速高效分离能力尚有待研究。本项目拟首先设计并可控制备具有优异磁分离和高效染料吸附性能的Fe3O4 亚微米内核/磷酸盐系磁性复合结构，系统研究其构效关系、吸附动力学及吸附机理，揭示材料的结构、成分对吸附性能的影响机制；系统研究磁性复合材料对多种不同染料的吸附特性，实现在复杂水体系中的高选择性吸附；研究吸附染料后复合材料的回收及循环使用特性，形成具有应用价值的吸附回收技术路线。本项目实施将有助于推动发展多功能高性能染料分子的无机复合材料技术，有助于深入理解该类复合材料高效、高选择性吸附染料分子的机理，对于水体中染料污染的有效控制具有重要的实验价值和理论指导意义。

本项目用水热法成功制备了磁性磷酸锶纳米棒、磁性磷酸锶钡复合纳米棒和磁性磷酸钡纳米片，并详细地研究了其对水中多种染料去除的特性及机理。结果表明所得的复合材料形貌规整、结晶性好，具有较高的饱和磁化强度和比表面积。尤其是Fe3O4纳米晶嵌入了磷酸盐晶格内，提升了复合材料的稳定性。经过吸附反应条件的优化，磁性羟基磷酸锶纳米棒对水中刚果红染料的吸附量可达396 mg/g，磁性磷酸锶钡复合纳米棒对水中酸性品红的吸附量高达1590 mg/g，磁性磷酸钡纳米片对水中甲基蓝染料的饱和吸附量达334.5 mg/g，高于之前的许多报道。吸附热力学数据用Langmuir、Freundlich、Temkin模型进行了拟合，动力学数据用一级动力学、二级动力学及颗粒间扩散模型进行了分析。在机理研究方面，扫描电子显微镜、红外光谱、X射线光电子能谱等结果表明磁性磷酸盐材料与有机染料之间主要形成了氢键和离子键作用。且这些复合材料可用普通磁铁方便地磁性回收，在经5次循环使用后，吸附量仍可达到初始饱和吸附量的80%以上，表现出了很好的应用前景。本项目研究的结果对磁性复合纳米材料的功能设计及染料污水处理方面的研究和应用具有一定的指导意义和实用价值。