Cauliflower-like alpha-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, Fe-57 Mossbauer spectrum, FESEM, TEM, N-2 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 alpha-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 alpha-Fe2O3 powders, the cauliflower-like alpha-Fe2O3 microstructures also exhibited higher visible-light photocatalytic degradation efficiency for rhodamine B in the presence of H2O2. (C) 2013 Elsevier B.V. All rights reserved.