Controlled synthesis and characterization of ZnSe nanostructures via a solvothermal approach in a mixed solution

In the present study, ZnSe nanostructures with complex morphologies and different phase structures were synthesized via a solvothermal approach using a mixed solution of triethylenetetramine (TETA) and de-ionized water (DIW). It was found that the phase and morphology of the as-prepared products could be controlled by changing the volume ratio of TETA to DIW. Metastable ZnSe nanoflowers with layered structure could be obtained from pure TETA, which can be transformed to the wurtzite structure after heat-treating at 500 °C in Ar atmosphere. With the addition of DIW, the morphology changed from flowers to spheres, and when the volume ratio of TETA to DIW was 1:1, loose spheres composed of nanoparticles were obtained. Variation of the TETA content in the mixed solvent also allows controlling of the crystallographic phase of ZnSe (wurtzite or zinc blende). Both the as-prepared products and the annealed powders were systematically characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared absorbance spectroscopy (FTIR), thermogravimetric analysis (TGA), and ultraviolet–visible (UV–vis) spectroscopy methods.