| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016) | |
| Nanomaterials | Wednesday Sessions |
| Session NM-WeP |
| Session: | Nanomaterials Poster Session |
| Presenter: | Arely Cano, CICATA Legaria, National Polytechnic Institute, México |
| Authors: | A. Cano, CICATA Legaria, National Polytechnic Institute, México A.A. Lemus-Santana, CICATA Legaria, National Polytechnic Institute, Mexico J. Tóth, Institute for Nuclear Research (ATOMKI), Hungarian Academy of Sciences, Hungary L. Kövér, Institute for Nuclear Research (ATOMKI), Hungarian Academy of Sciences, Hungary E. Reguera, CICATA Legaria, National Polytechnic Institute, México |
| Correspondent: | Click to Email |
Zn3A2[Fe(CN)6]∙xH2O with A= Na+, K+, Rb+ shows a high ability for Cs+ removal from aqueous solutions by ionic exchange.These solids have a porous framework formed by six large ellipsoidal cavities per hexagonal unit cell with dimensions close to 15.5x11.1x7.9 Å. The neighboring cavities remain connected by elliptical windows of about 6.8x8Å. Within a given cavity two charge balance cations A+ are found. These cations are located close to N corners of the ZnN4 tetrahedron [1]. For Cs+ the ionic exchange is highly favorable due of its large volume [2], the Cs+ ion is found interacting with two N neighboring atoms. This explains that when Zn3A2[Fe(CN)6]2∙xH2O is immersed in an aqueous solution containing Cs+, the ionic exchange is quantitative. On the other hand, the iron oxides nanoparticles have attracted attention as simple, efficient and economical materials for pollutant removal, including heavy metals. Their physicochemical properties as large surface areas, surface reactivity and strong adsorption capability can be modified and enhanced to obtain effective adsorbents materials. In addition, the iron oxide behaves as ferrimagnetic or ferromagnetic material; such property can be used to allow the separation process using an applied magnetic field. This is the case of the system under study in this contribution. In this study, paramagnetic magnetite nanoparticles were synthesized and covered with a thin shell of Zn3A2[Fe(CN)6]2, then the shell was progressively growing at the surface. The nanocomposi tes obtained were evaluated for Cs+ removal from aqueous solutions. For evaluation, the nanocomposites were prepared with different iron oxide particles sizes and Zn3A2[Fe(CN)6] thin shell . The structural study was carried out from XRD powder patterns and Electron Microscopy data.
The interactions at the interface between the core of magnetite nanoparticles and the zinc hexacyanoferrate shell were studied by X-ray Photoelectron Spectroscopy (XPS) and Mössbauer spectroscopy. The nanocomposites studied were prepared by two different successive adsorption cycles of shell growth, Fe3O4@[Fe(CN)6]4- and Zn2+. The quantitative analysis by XPS allows determine the shell thickness using an appropriate model and supported with Mössbauer data which allows the identification of species formed and their interactions at the interface.