Water bath synthesis and enhanced photocatalytic performances of urchin-like micro/nanostructured α-FeOOH

Micro/nanostructured goethite (α-FeOOH) was synthesized by a low-temperature water bath method based on the reaction of urea and FeSO4•7H2O at 95 °C. It has been shown that the as-prepared α-FeOOH consists of nearly spherical particles with about 0.5–1 µm in diameter. The microsized α-FeOOH particles are urchin-like in morphology and composed of nanosized leaf-like objects, with about 150–200 nm in length and about 30–50 nm in width, in radial arrangement, showing high specific surface area (∼118 m2/g). The formation of such urchin-like α-FeOOH could be described by a two-step process, or formation of spherical particles, and ethylene glycol-adsorption induced preferential growth of nanoleaves on the preformed spherical particles. Importantly, such micro/nanostructured α-FeOOH has exhibited much higher photocatalytic activity to the organic pollutants, such as Rhodamine 6G, and better re-usable performances than the goethite nanorod powders, exhibiting the good application potential in the environmental treatment. This study could provide a useful material for environmental pollution treatment.