A novel "green" synthesis of starch-capped CdSe nanostructures

This paper reports a "green" facile, room temperature, one-pot synthesis of starch-capped CdSe nanostructures with an obvious quantum confinement effect via a novel non-organometallic method. It is found that by simply tuning the Cd:Se molar ratio, dots and elongated particles of high aspect ratio could be prepared selectively in the presence of the same ligand concentration without any post-treatment. Spherical particles were produced at 1:1 ratio, while elongated particles were produced at 0.5:1 Cd:Se ratio. The X-ray diffraction (XRD) analysis showed that the particles were predominantly of wurtzite structure, with sharp diffraction patterns regardless of their size and shapes. We inferred that the elongated particles are formed by self-reorganisation occurring via adhesion between the spherical nanoparticles as a result of dipole-dipole interactions.