Selective growth of crystalline SnO2 on the polar surface of ZnO nanobelts

A novel nanostructure of a side-to-side SnO2/ZnO/SnO2 triaxial nanobelt has been achieved via a simple oxidation of the separated Zn and Sn powders. Each nanobelt has a broad inner ribbon of ZnO with two symmetric SnO2 sides, and all of the belts are single crystal. This composite structure demonstrates the possibility of selective growth based on the polar surface and also suggests that heterogeneous growth can proceed on both polar surfaces of ZnO +/- (0001). The corresponding room-temperature photoluminescence has also been tailored and been discussed in this paper. Our approach presented here would be helpful in designing and preparing many other heterostructures to meet the growing demands of nanoscale science and technology.