A Critical Textural Evolution Study of Zerovalent Iron/Montmorillonite Nanosized Heterostructures Under Various Iron Loadings

Abstract

Abstract-Heterostructures formed by nanoparticles hybridized with porous hosts are of great potential in many practical applications such as catalysis, adsorption, and environmental remediation, based on their intrinsic properties. The objectives of this study were to synthesize zerovalent iron nanoparticles/ montmorillonite heterostructures and to investigate their textural evolution under different Fe loadings. Iron nanoparticles were hybridized with montmorillonite by impregnation of montmorillonite by ferric ions followed by chemical reduction with sodium borohydride in solution. These hybridized Fe nanoparticles were well dispersed on the montmorillonite surface, size adjustable, and resistant to oxidation under the protection of native Fe-oxide shells. The textural evolution of these heterostructures under various Fe loadings was investigated using nitrogen physisorption, X-ray diffraction, electron microscopy, and elemental analyses. As the Fe loadings increased, the total pore and mesopore volumes were almost unchanged; the total, micropore, and external surface areas as well as the micropore volume decreased; and the average pore diameter increased. These textural changes could be attributed to the filling of the interparticle pores of montmorillonite by a variable amount of Fe nanoparticles. In addition, with increasing Fe loadings, the mesoporous character was enhanced for these heterostructures. These fundamental results are important in understanding the structure of these heterostructures as well as in developing some novel applications in related fields.

Iron-containing nanomaterials: synthesis, properties, and environmental applications

“…NZVI/montmorillonite heterostructures were synthesized and their textural evolution under different Fe loadings was investigated. 104 The hybridized Fe nanoparticles were well dispersed on the montmorillonite surface, size adjustable, and resistant to oxidation under the protection of native Fe-oxide shells. It was revealed that as the Fe loadings increased, the total pore and mesopore volumes remained almost unchanged but the total, micropore and external surface areas as well as the micropore volume decreased and the average pore diameter increased.…”

Nanosized magnetite in low cost materials for remediation of water polluted with toxic metals, azo- and antraquinonic dyes

“…Their adsorption capacity resulted from a relatively high surface area and a net negative charge on their structure, which attracted specially cations. On the other side, the presence of magnetite provided the advantage to the material be removed from the medium by a simple magnetic field [87].…”