Assembly of -Fe2O3 Rubik's nanostructure with adsorptive property

The -Fe2O3 nanocrystals with a size of about 60 nm were prepared by using FeCl3 and NaOH as precursors through a facile and green three-step hydrothermal reaction process. Then, using the resulting -Fe2O3 nanocrystals as basic materials, the -Fe2O3 Rubik's nanostructures were fabricated by a self-assembly method under ultrasonic condition, due to the platelet-shaped structure and magnetic property of the -Fe2O3 nanocrystals. Interestingly, the resulting Rubik's nanostructures with a diameter of 300-600 nm exhibit typical room-temperature ferromagnetism, and could serve as an adsorbent to quickly remove the trace-level (50 mg L−1) Pb2+ from water. It provides options for developing new preparation technology of Fe2O3-based nanomaterials for many applications.