Solvothermal route to novel TiO2 capped ZnS nanowires

A facile solvothermal route was designed to fabricate novel TiO2/ZnS heterostructures by using polar wurtzite ZnS nanowires and TiO2 nanotubes as starting materials. In the solvothermal process. TiO2 nanotubes were first transmitted into amorphous TiO2 nuclei. Then, the TiO2 nuclei were further regularly grown at one tip of the ZnS nanowires to form TiO2 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, TiO2 nanoparticles were selectively grown on Zn-terminated (0001) facets of ZnS nanowires. (C) 2011 Elsevier B.V. All rights reserved.