Fabrication of self-assembled iron oxide hierarchical nanostructures and their application in water treatment

A facile hydrothermal approach based on n-nonyl alcohol mediated process has been developed to synthesize self-assembled Fe3O4 hierarchical nanostructures. The as-synthesized hierarchical nanostructured Fe3O4 could be easily transformed to γ-Fe2O3 and α-Fe2O3 without changing its original morphology by calcination in air. X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) were performed to investigate the evolution process of Fe3O4 hierarchical nanostructures. The growth mechanism of the as-prepared Fe3O4 nanostructure and the subsequently hierarchical nanostructures are suggested. The as-obtained iron oxide nanomaterials were used as adsorbent in water treatment, and were found an excellent ability to remove organic pollutants such as Orange II in waste water.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Fe3O4 hierarchical nanostructures have been prepared via a facile hydrothermal method. ► The as-synthesized Fe3O4 could be easily transformed to γ-Fe2O3 and α-Fe2O3 with the same hierarchical nanostructures. ► The as-obtained iron oxide nanomaterials have an excellent ability to remove organic pollutants.