Fabrication and structure characterization of MnCO3/α-Fe2O3 nanocrystal heterostructures

Novel MnCO3/α-Fe2O3 nanocrystal heterostructures, with MnCO3 nanorods 5–10 nm in diameter and 15–50 nm in length, grown onto the surfaces of the α-Fe2O3 nanohexahedrons sized around 30–50 nm, were fabricated via a two-step solvothermal route. The coalescent planes of the heterostructure for the MnCO3 nanorod and the α-Fe2O3 nanohexahedron were determined to be (01̅4) and (110), respectively. The formation of the MnCO3 nanorods from the Mn contained amorphous flakes was tracked by transmission electron microscopy observations at various reaction stages, which suggested a rolling–broken–growth process. Evidenced by the comparative experimental result, the α-Fe2O3 nanohexahedrons played an important role in inducing the nucleation and growth of the hexagonal MnCO3 nanorods on their surfaces.