Facile solid-state synthesis of Fe/FeOOH hierarchical nanostructures assembled from ultrathin nanosheets and their application in water treatment

Abstract

Iron-based hierarchical nanostructures with enhanced properties have attracted intense interest as sorbents for water treatment. It is important to design a facile and scalable procedure for the preparation of absorbents with hierarchical structures. Here, a green solid-state method for the fabrication of Fe/FeOOH hierarchical nanostructures (Fe-HNs) is developed. The obtained samples with sizes in the range of 500–800 nm are three-dimensional (3D) hierarchical structures assembled from ultrathin nanosheets. A plausible “reduction–oxidation” mechanism is proposed for the formation process of the Fe-HNs. The as-prepared Fe-HNs are utilized as an adsorbent for the removal of Congo red and Cr(VI) ions from aqueous solution. The results show that the adsorbent exhibits high adsorption capacity, fast adsorption rate, and superior magnetic isolation. These Fe-HNs prepared by a facile solid-state method display very promising potential application in water treatment as an adsorbent.