The fractal splitting growth of Sb2S3 and Sb2Se3 hierarchical nanostructures

Complex Sb2S3 and Sb2Se3 nanostructures with a sheaf-like hierarchical morphology were prepared on a large scale at 180 degrees C by a simple hydrothermal method in the presence of poly(vinyl pyrrolidone) (PVP). X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy were used to characterize the products. The results indicate that three-dimensional Sb2S3 and Sb2Se3 complex nanostructures were constructed by fractal splitting growth. The time-dependent shape-evolution process suggests that initial stages of the growth comprise nanorod seeds. These PVP-stabilized nanorods develop in subsequent growth stages to a dumbbell structure and complete their development as a closed sphere with an equatorial notch. It has been demonstrated that PVP plays a key role in the formation of such hierarchical nanostructures. Ultraviolet-visible-near-infrared spectroscopy was further employed to estimate the band gap energy of the obtained products. The measurements of the optical properties revealed that the obtained materials have a band gap of 1.56 eV for Sb2S3 and 1.13 eV for Sb2Se3. Our work may shed some light on the design of other well-defined complex nanostructures, and the as-grown architectures may have potential applications.