Synthesis of SrCrO4 nanostructures by onion inner-coat template and their optical properties

This paper describes a bio-template method of the squama inner coat of onion for preparing the SrCrO4 nanostructures including nanospheres, nanorods and dumbbell-shaped superstructure. The method is able to make SrCrO4 nanoparticles with average diameters in the range of 90–170 nm, SrCrO4 nanorods with length in the range 0·70–2 μm, width in the range of 80–180 nm, and SrCrO4 dumbbell-shaped superstructure with length in the range 10–14 μm. The dumbbell-shaped superstructures are assembled by many SrCrO4 nanowires with length in the range 10–14 μm and width in the range 30–50 nm. The products were characterized by transmission electron microscope, powder X-ray diffraction, UV-Vis spectroscopy and luminescence spectrophotometer. A possible formation mechanism was also proposed. In the preparation, the SrCrO4 nanostructures were synthesized at room temperature without any surfactants. This new bio-template method will have potential applications in preparation of the nanoscale materials with different morphologies.