Microemulsion-mediated hydrothermal synthesis and characterization of zircon-type LaVO4 nanowires

The zircon-type tetragonal (t-) LaVO4 nanowires were controlled synthesized by a new approach, a microemulsion-mediated hydrothermal method, in which the aqueous cores of sodium dodecyl sulfate (SDS)/cyclohexane/n-hexanol/water microemulsion were used as constrained microreactors for a controlled growth of t-LaVO4 nanocrystals under hydrothermal conditions. The microemulsion exists stably just at room temperature and not under hydrothermal conditions, in addition, the as-obtained nanowires are much larger than the microemulsion droplets, so that the microemulsion does not simply act as a template, but rather directs crystal growth into nanowires presumably by interacting with the surface of the growing crystal. A series of experimental results indicated that several experimental parameters, such as the SDS concentration, the species and content of the cosurfactant play important roles in the morphological control of the t-LaVO4 nanocrystals. Possible formation mechanism of t-LaVO4 nanowires is also discussed.