Surfactant-assisted nanorod synthesis of α-FeOOH and its adsorption characteristics for methylene blue

Sodium dodecyl sulfate (SDS) was chosen as the structure controller and surface modifier for hydrothermal preparation of surfactant-modified goethite (α-FeOOH) nanorods. The as-synthesized samples were characterized by transmission electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, Brunauer, Emmett and Teller technique, and potentiometric titration. Adsorption study using methylene blue (MB) as a model pollutant was conducted onto the surfactant-modified goethite surface. The results showed that the surfactant-modified α-FeOOH nanorods had high adsorption capacity. MB could be efficiently removed from the solution at pH 5, initial MB concentration 200 mg/L, α-FeOOH dosage 0.5 g/L, and temperature 30 °C, with 96% removal ratio. The adsorption capacity was found to be as high as 385 mg/g. The adsorption kinetic data could be described well by the pseudo-second-order model. The isothermic data were highly fitted to Langmuir isotherm. High adsorption capacity and simple reaction conditions give this novel material good prospects in future applications.