Novel nanocrystal heterostructures:: Crystallographic-oriented growth of SnO2 nanorods onto α-Fe2O3 nanohexahedron

The novel SnO2/alpha-Fe2O3 semiconductor nanocrystal heterostructures (SNCHs) were fabricated by virtue of the crystallographic-oriented growth of the SnO2 nanorods onto the alpha-Fe2O3 nanohexahedrons via a reverse microemulsion route. The variation of the exposure surfaces of the alpha-Fe2O3 precursor crystals was found to result in the change of the preferential crystallographic orientation of the SnO2 nanorods. The investigations on the structural characteristics and the morphological evolution of the SnO2/alpha-Fe2O3 SNCHs suggested that the heteronucleation and homonucleation of SnO2 occurred simultaneously at the early stage of the reaction, and the SnO2/alpha-Fe2O3 SNCHs were then well-formed by a mechanism of Ostwald ripening of the heteronucleated SnO2 particles. The "lattice dislocations" generated at the SnO2/alpha-Fe2O3 interfaces took the role to relieve the interfacial strain and thus facilitated the formation of the definite interfaces.