Deep Separation Between In(III) and Fe(III) Ions by Regulating the Lewis Basicity of Adsorption Sites on Electrospun Fibers

Abstract

The deep separation between In(III) and Fe(III) ions is considered as an important technological challenge in the engineering fields. The In(III) ions are closer to the soft acid in terms of Lewis acidity due to the smaller polarizability and greater deformability than the Fe(III) ions, which facilitates the possibility of separating them. Herein, the Lewis basicity of the N‐containing adsorption sites is regulated by the fluorine‐containing group to better match with the In(III) ions rather than Fe(III) ions, causing a significant discrepancy in the binding of the adsorption sites to them. Moreover, targeted programmed desorption techniques based on the potential energy differences of the adsorption sites can achieve the deep separation of In(III) and Fe(III) ions, and reach an exceptional concentration of 20.7 mmol L−1 for In(III) ions in the initial desorption solution with extremely high mass ratio (mIn/mFe = 151.7). This work provides a novel technique for in‐depth separation of In(III) and Fe(III) ions from mixed systems, and a new strategy for separating metal ions with similar or close properties.

Advanced Electrospinning Technology Applied to Polymer-Based Sensors in Energy and Environmental Applications

“…Li et al [ 100 ] utilized the Lewis basicity of nitrogen-containing adsorption sites to regulate the fluorinated groups, better matching with In (III) ion cations, resulting in significant differences in the binding of adsorption sites to them, shown in Figure 9 a. In addition, a targeted program is adopted for desorption technology based on the potential energy difference of adsorption sites.…”

“… ( a ) Schematic diagram of the preparation process of perfluorooctanoic acid nanofibers, along with SEM and EDS elemental map images and corresponding diameter distribution [ 100 ]. Copyright 2023, reproduced with permission from Wiley.…”