α-ZrP/PANI电控离子交换膜对Pb2 的选择性分离

Selective Separation of Pb2 with Electrochemically Switched ion exchange film of α-ZrP/PANI

摘要:

采用电化学方法在水相中合成了一种新型的电活性α-磷酸锆(α-ZrP)/聚苯胺(PANI)阳离子交换材料,考察该膜在含Pb₂ 溶液中的电控离子交换性能。分别在碳纳米管(CNTs)和PANI纳米纤维修饰的Au基体上制备了不同结构的α-ZrP/PANI杂化膜,并结合电化学石英晶体微天平(EQCM)技术,原位检测杂化膜的生长过程,分析其成膜机理。研究结果表明,在PANI纤维上制备的杂化膜因其三维多孔结构具有更高的离子交换容量；α-ZrP上的P-OH不仅能够为聚苯胺氧化还原提供氢质子,而且对Pb₂ 表现出良好的吸附选择性,使该膜在中性含Pb₂ 溶液中表现出良好的电活性。通过控制该杂化膜的氧化还原状态可以实现对重金属Pb₂ 离子的选择性分离和回收。

Abstract:

A novel electroactive α-ZrP/PANI hybrid film with cation exchange property was synthesized by electrochemical method in aqueous solution. The electrochemically switched ion exchange capacity of this film was investigated in 0.1 M Pb(NO₃)₂. The α-ZrP/PANI hybrid films with different structures were prepared on carbon nanotubes (CNTs) and PANI nanofibers modified Au electrodes. The fabrication process and formation mechanism were analyzed by electrochemical quartz crystal microbalance (EQCM). The results shows that the hybrid film prepared on PANI fibers exhibited higher ion exchange capacity because of its three-dimensional porous structure; The P-OH of α-ZrP not only provides protons for the redox of PANI but also shows adsorption selectivity for Pb₂ , which makes this hybrid film perform good electroactivity in neutral solution containing Pb₂ . Therefore, this hybrid film could be served as an ESIX material for separation and recovery of Pb₂ by controlling the oxidation-reduction of hybrid film.