Hydrothermal Synthesis, Structural Characteristics, and Enhanced Photocatalysis of SnO2/α-Fe2O3 Semiconductor Nanoheterostructures

Branched SnO2/alpha-Fe2O3 semiconductor nanoheterostructures (SNHs) of high purity were synthesized by a low-cost and environmentally friendly hydrothermal strategy, through crystallographic-oriented epitaxial growth of the SnO2 nanorods onto the alpha-Fe2O3 nanospindles and nanocubes, respectively. It was demonstrated that the SnO2 nanorods would change their preferential growth direction on the varied alpha-Fe2O3 precursors with distinct crystallographic surface, driven by decrease in the distortion energy induced by lattice mismatch at the interfaces. All of the prepared SNHs were of high purity, ascribing to the successful preinhibition of the SnO2 homonucleation in the reaction system. Significantly, some of the SnO2/alpha-Fe2O3 SNHs exhibited excellent visible light or UV photocatalytic abilities, remarkably superior to their alpha-Fe2O3 precursors, mainly owing to the effective electron-hole separation at the SnO2/alpha-Fe2O3 interfaces.