结构调节剂辅助水热法制备分等级Mg-Al水滑石焙烧产物及其Cr(VI)吸附性能  

Preparation and Cr(VI)adsorption of hierarchical calcined Mg-Al layered double hydroxides via structure directing agents assisted hydrothermal method

作　　者：李广济[1] 蔡卫权[1] 谈立君[1] 吴选军[1] 

机构地区：[1]武汉理工大学化学工程学院,武汉430070

出　　处：《化工新型材料》2014年第5期113-116,共4页New Chemical Materials

基　　金：国家自然科学基金(51272201);教育部新世纪优秀人才支持计划(NCET-13-0942);武汉市青年科技晨光计划(2013070104010002);中央高校基本科研业务费专项资金(2013-II-014)资助项目

摘　　要：以廉价的硝酸镁为镁源、硝酸铝为铝源、尿素为沉淀剂,分子量或化学结构不同的P123、F127和聚丙烯酸钠为结构调节剂,采用水热均相沉淀—焙烧法成功地制备出系列分等级多孔Mg-Al水滑石焙烧产物(LDOs)。采用X射线衍射(XRD)、扫描电镜(SEM)、氮气吸附-脱附和UV紫外分光光度计等手段,对产物的物相、形貌和织构性质及其对重金属Cr(VI)的吸附性能进行了比较表征和测试。研究发现,以P123为结构调节剂时制备的微米级椭球体和棒状结构共存的LDO的比表面积为131.8m2/g、孔容为0.31cm3/g、平均孔径为9.6nm,一定条件下其对Cr(VI)的平衡吸附量达46.5mg/g,该吸附过程符合拟二级动力学模型。A series of hierarchical porous calcined Mg-Al Layered Double Hydroxides（LDOs）were successfully prepared by hydrothermal homogeneous precipitation and followed by calcination method using cheap magnesium nitrate as magnesium source,aluminum nitrate as aluminum source,urea as precipitation agent,P123,F127and sodium polyacrylate with different molecular weight or chemistry structure as the Structure Directing Agents（SDAs）.The phase structure, morphology,textural properties and Cr（VI）adsorption performance of the as-prepared samples were comparatively characterized and measured by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,nitrogen adsorption-desorption technique and UV-Vis spectrophotometric method.It was found that the microscale Mg-Al LDO with coexisted spheroid and rod-like structure using P123as the SDA had a specific surface area of 131.8m2/g,pore volume of 0.31cm3/g and average pore size of 9.6nm,and its equilibrium adsorption capacity can reach 46.5mg/g under certain conditions.The adsorption process matched the pseudo-second-order kinetic model well.

关 键 词：Mg-Al水滑石焙烧产物 结构调节剂 吸附 CR(VI) 分等级结构 

分 类 号：O611.4[理学—无机化学] O647.3[理学—化学]