Electrochemically Switched Ion Exchange Properties of PANI-SnP Composite Films in Wastewater Containing Ni2+ and Cd2+

Abstract

采用滴涂法在铂基底制备了电活性聚苯胺-磷酸锡(PANI-SnP)复合膜电极,考察了该电极在Ni2+、Cd2+溶液的电控离子交换性能. 用傅立叶变换红外光谱和扫描电镜分析观察复合膜的组成及表面形貌;在0.1 mol·L-1 Ni(NO3)2、Cd(NO3)2溶液,通过循环伏安法比较了PANI膜、SnP膜及PANI-SnP复合膜电极的电化学性能,并结合电化学石英晶体微天平技术重点考察了PANI-SnP复合膜的离子交换机制;同时,通过循环伏安法调控复合膜电极的氧化还原电位,结合X射线能谱和X射线光电子能谱分别测定了其氧化和还原状态的元素组成. 结果表明,PANI-SnP复合膜电极在Ni2+、Cd2+溶液均有良好的氧化还原电活性和可逆离子交换性能,其Cd2+离子选择性优于Ni2+离子,通过电控离子交换可使Cd2+离子从镍镉废水高效分离.Electroactive PANI-SnP composite films were prepared by drop-coating method on Pt electrodes and investigated as electrochemically switched ion exchange (ESIX) materials for the separation of Cd2+ from aqueous solutions. The composition and morphology of the composite film were characterized by Fourier transform infrared spectrometer (FTIR) and scanning electron microscope (SEM). In solutions containing 0.1 mol·L-1 Ni(NO3)2 and Cd(NO3)2, cyclic voltammetry (CV) and electrochemical quartz crystal microbalance (EQCM) were used to investigate the electrochemical behavior and ion-exchange mechanism of PANI-SnP composite film. The elementary composition of PANI-SnP composite films in both oxidation and reduction states were also characterized by energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Experimental results show that the PANI-SnP composite films have reversible electrochemical behavior in aqueous solutions containing Cd2+ and Ni2+, respectively. The PANI-SnP composite film electrodes displayed a high selectivity toward Cd2+ in Cd2+/Ni2+ binary mixtures and the Cd2+ ions could be separated effectively from aqueous solutions by ESIX processes.国家自然科学基金(No. 20676089),山西省自然科学基金(No. 2012011020-5, No. 2012011006-1),山西省国际科技合作计划项目(No. 2011081028)资助作者联系地址:太原理工大学化学化工学院化学工程系,山西 太原 030024Author's Address: Department of Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China通讯作者E-mail:[email protected]

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