Hydrothermal synthesis of monodisperse dodecahedron α-Fe2O3 nanocrystals with high photocatalytic activity

Novel alpha-Fe2O3 dodecahedron nanocrystals were prepared by a facile one-step hydrothermal method without using any templates. The samples were analyzed by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, respectively. The results revealed that the as-prepared nanocrystals with the average diameters of 200 nm are well-shaped symmetric hexagonal bipyramidal structure. The homogeneous dodecahedron nanoparticles were obtained by optimizing the experimental conditions including reaction temperatures and time. A possible formation mechanism was also proposed. To demonstrate potential applications, the photocatalytic activity of the as-prepared samples was evaluated by photo-degradation of rhodamine B from aqueous solution at room temperature. Results show that the alpha-Fe2O3 dodecahedron with exposed (012) plane exhibits significantly improved photocatalytic activities for degradation of rhodamine B in aqueous solution under visible light irradiation.