沉淀剂对水热法制备分等级氧化铁纳米结构及其Cr(Ⅵ)吸附性能的影响  

Effects of Precipitation Reagents on the Hierarchical Iron Oxide Nanostructures via Hydrothermal Method and Their Adsorption Performance Towards Cr(Ⅵ)

作　　者：王珺[1] 蔡卫权[1,2] 吴选军[1] 

机构地区：[1]武汉理工大学化学化工与生命科学学院,武汉430070 [2]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉430070

出　　处：《无机化学学报》2014年第11期2564-2570,共7页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.51272201和No.21476179);教育部新世纪优秀人才支持计划(No.NCET-13-0942);武汉市青年科技晨光计划(No.2013070104010002);中央高校基本科研业务费专项资金(No.2013-II-014);材料复合新技术国家重点实验室(武汉理工大学)开放基金(2013-KF-5);武汉理工大学2013年自主创新研究基金本科生项目(2013-HG-B2-12)资助项目

摘　　要：以硫酸铁为铁源、硫脲、氟化钠和尿素分别为沉淀剂,采用水热法成功地制备了分等级微米级球状氧化铁粒子、六方柱状粒子相互交织的微米级氧化铁团聚体等。采用X射线衍射、扫描电镜、N2吸附-脱附、磁滞回线和UV紫外分光光度计等测试手段,对比研究了上述沉淀剂对产物微结构、形貌、织构性质及其对剧毒Cr(Ⅵ)吸附性能的影响。结果表明,以硫脲为沉淀剂制得氧化铁的结晶度最高,其晶粒大小为49.7nm,并具有最高的比表面积13.0m2·g-1、最大的孔容0.092cm3·g-1和平均孔径28.6nm;该氧化铁具有最佳的Cr(Ⅵ)吸附性能,30min即达到吸附平衡,饱和吸附量达202.8mg·g-1,并且符合Langmuir单分子层吸附模型;该氧化铁还具有一定的磁性,通过外加磁场可以实现吸附Cr(Ⅵ)后的吸附剂与溶液的彻底分离,因而在重金属废水处理领域显示出良好的应用前景。Hierarchical microscale iron oxide particles including spherical-like structure, aggregates composed of intertwined hexagonal prism were successfully prepared via hydrothermal method using ferric sulfate as iron source, thiourea, sodium fluoride and urea as precipitants, respectively. Effects of the precipitants on the microstructures, morphologies, textural properties of the as-prepared materials and their adsorption performance towards highly toxical Cr （Ⅵ） were comparatively studied by X-ray diffraction, scanning electron microscopy, N2adsorption-desorption, hysteresis loop and UV/Vis spectrophotometer. It was found that the iron oxide precipitated from thiourea has the highest crystallinity with a crystal size of 49.7nm, the highest specific surface area of 13.0m^2·g^-1, the biggest pore volume of 0.092 cm^3·g^-1and an average pore size of 28.6 nm. This iron oxide shows the optimal adsorption performance with a highly maximum adsorption capacity of 202.8 mg·g^-1within 30 min, and its adsorption process fits Langmuir monolayer adsorption well. Furthermore, its certain magnetism can realize complete separation between the adsorbent with adsorbed Cr （Ⅵ） and solution, and thus shows a good application prospect on heavy metal wastewater treatment.

关 键 词：硫脲 水热法 吸附 Cr(Ⅵ) 磁分离 

分 类 号：O614.811[理学—无机化学] O614.611[理学—化学]