Related Experiment Video
Updated: May 21, 2026

Seeded Synthesis of CdSe/CdS Rod and Tetrapod Nanocrystals
Published on: December 11, 2013
Redox-assisted asymmetric ostwald ripening of CdSe dots to rods
Rongfu Li1, Zhengtang Luo, Fotios Papadimitrakopoulos
1Nanomaterials Optoelectronics Laboratory, Polymer Program, Institute of Materials Science, Storrs, Connecticut 06269-3136, USA.
Abstract:
The redox-assisted asymmetric Ostwald ripening of dots to rods was observed upon annealing a concentrated dispersion of CdSe nanocrystals (NCs) containing 0.1 M CdCl2 in 3-amino-1-propanol (APOL)/H2O (v/v = 9/1) at 135 degrees C. Transmission electron microscopic investigation, along with UV-vis and photoluminescence results, revealed that, while the length of these NCs increased upon annealing, their diameter remained constant. The surface oxidation of NC Se atoms to SeO2 and its subsequent dissolution into the basic APOL/H2O mixture as SeO32- was found instrumental for such dot-to-rod transformation. The amine-assisted SeO2 reduction to Se0 (as confirmed by X-ray photoelectron spectroscopy and X-ray diffraction results) provides the Se source for further NC growth. The preferential growth along the c-axis leads to the formation of rods with zinc blende CdSe structure at its growing ends, due to the low-temperature growth conditions.
Related Concept Videos
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Diels–Alder Reaction: Characteristics of Dienes
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is more stable, the...
Differential Staining Technique

