Selective growth of TiO2 tips on CdSe nanowires

We developed a solvothermal route to one-dimensional TiO2-CdSe heterostructures using wurtzite CdSe nanowires and TiO2 nanotubes as source materials. Amorphous TiO2 nanoparticles are selectively deposited at one tip of the CdSe nanowires, resulting in the unique TiO2 capped CdSe nanowire heterostructures. It is found that the differences of chemical reactivity among various facets are the main reason for the heterostructures. Chemical reactivity of the Se terminated (0001¯) is most reactive, and the selective nucleation and growth of TiO2 nanoparticles only occur on the most reactive Se-terminated (0001¯) facets of the CdSe nanowires.