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 mu m, width in the range of 80-180 nm, and SrCrO4 dumbbell-shaped superstructure with length in the range 10-14 mu m. The dumbbell-shaped superstructures are assembled by many SrCrO4 nanowires with length in the range 10-14 mu m 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.