介孔α-Fe_2O_3表面配合反应平衡常数测定

Surface Complexation Constants of Mesoporous Fe_2O_3

采用十二胺为模板剂、氨水做沉淀剂成功制备了介孔α-Fe2O3,通过粉末X射线衍射(XRD)、透射电镜(TEM)、N2吸附/脱附技术对样品晶相、形貌和比表面积进行了表征.根据介孔α-Fe2O3悬浮液的酸碱滴定数据,使用FITEQL软件,采用双电层恒电容模型计算得出了介孔α-Fe2O3的表面酸碱反应平衡常数.在此基础上研究了Cu2+,Pb2+,Zn2+在介孔氧化铁表面的吸附行为,使用WinSGW软件模拟得出了相应的表面配合反应平衡常数并讨论了其吸附机理.

Mesoporous Fe2O3 nanoparticles were synthesized using dodecyl amine as a template and ammonia as a precipitant.Powder X-ray diffraction （XRD）,transmission electron microscopy （TEM）,and nitrogen adsorption-desorption analysis methods were used to characterize the crystallinity,morphology and the specific surface area.According to the experimental data of acid base titration of mesoporous α-Fe2O3 suspension,using FITEQL software and Constant Capacitance Model （CCM）,the protonation and deprotonation constants of mesoporous α-Fe2O3 were determined.Base on the acid-base constants the adsorption of heavy metal ions （Cu^2＋,Pb^2＋,Zn^2＋） at the surfaces of mesoporous Fe2O3 was studied as a function of pH.The surface complexation constants of Cu^2＋,Pb^2＋,Zn^2＋at the surfaces were determined using WinSGW software and the reaction mechanism was discussed as well.