Synthesis and photoluminescent properties of strontium tungstate nanostructures

Strontium tungstate nanoparticles with diameters of 40-50 nm, nanopeanuts with diameters of 100-150 nm, and nanorods with a rough surface were controllably synthesized by a solvothermal-mediated microemulsion method. Various comparison experiments showed that several experimental parameters, such as the molar ratio (w) between water and CTAB and the concentration of reactants, played important roles for the morphological control of Sr(NO ₃)₂ nanostructures. When the concentration of the Sr(NO₃)₂ aqueous solution was kept at 0.3 M, the morphology of the as-synthesized products elongated from nanospheres, to nanopeanuts, and to nanorods with the increase of the w value. A possible mechanism is proposed for the selective formation of the different morphologies. The SrWO₄ samples with different morphologies exhibited different photoluminescent properties. X-ray powder diffraction, transmission electron microscopy, selected area electron diffraction, and field-emission scanning electron microscopey were used to characterize these products.