Cauliflower-like α-Fe2O3 microstructures: Toluene–water interface-assisted synthesis, characterization, and applications in wastewater treatment and visible-light photocatalysis

• Novel cauliflower-like α-Fe2O3 was synthesized at the toluene–water interface.
• It exhibited uniquely hierarchical architecture.
• It can be used as an efficient adsorbent for Cr(VI), Pb(II) and Congo red removal.
• It showed remarkable visible-light photocatalytic activity in the presence of H2O2.

Cauliflower-like α-Fe2O3 microstructures constructed by nanoparticle-based buds were successfully synthesized in large quantities through a one-step toluene–water biphasic interfacial reaction route. The samples were characterized by XRD, 57Fe Mössbauer spectrum, FESEM, TEM, N2 adsorption–desorption isotherm, and UV–visible diffuse reflectance spectroscopy. Experimental results demonstrated that the interface system, reaction temperature, and Fe(acac)3 concentration had important effects on the structures and morphologies of the as-synthesized samples. Based on the time-dependent experimental results, a possible mechanism for the formation of the cauliflower-like microstructures was speculated. The obtained cauliflower-like α-Fe2O3 microstructures have high BET surface area, 3D hierarchical and porous structure and showed excellent adsorption performances for organic dye and heavy metal ions in water treatment. Furthermore, compared to the commercial α-Fe2O3 powders, the cauliflower-like α-Fe2O3 microstructures also exhibited higher visible-light photocatalytic degradation efficiency for rhodamine B in the presence of H2O2.

Cauliflower-like α-Fe2O3 microstructures constructed by nanoparticle-based buds were synthesized through a one-step toluene–water biphasic interfacial reaction route. Such unique hierarchical microstructures were shown to exhibit excellent water treatment performance with high removal capacities for organic dye and heavy metal ions and structurally enhanced visible-light photocatalytic activity in the degradation of rhodamine B in the presence of H2O2 compared to the commercial α-Fe2O3 powders.Figure optionsDownload as PowerPoint slide