Solvothermal route to novel TiO_2 capped ZnS nanowires

摘要

A facile solvothermal route was designed to fabricate novel TiO_2/ZnS heterostructures by using polar wurtzite ZnS nanowires and TiO_2 nanotubes as starting materials. In the solvothermal process, TiO_2 nanotubes were first transmitted into amorphous TiO_2 nuclei. Then, the TiO_2 nuclei were further regularly grown at one tip of the ZnS nanowires to form TiO_2 capped ZnS nanowire heterostructures. It is found that polarity of ZnS nanowires plays an important role for the novel heterostructures. The reactivity of the polar ZnS nanowires with [0001] growth direction is higher at the tips than along the body due to the increased surface energy. Moreover, the Zn-terminated (0001) facets are chemically active in the growth of wurtzite nanowires compared with S-terminated (000-1) facets. Thus, TiO_2 nanoparticles were selectively grown on Zn-terminated (0001) facets of ZnS nanowires.