Transformation of Se@Ag₂Se Core−Shell Colloids and Nanowires into Trigonal Se Nanorods and Uniform Spherical Ag₂Se Colloids

Abstract

Physical separation of Ag(2)Se colloids and trigonal (t) Se nanowires transformed from amorphous (a) Se@Ag(2)Se core-shell spherical colloids and from t-Se@Ag(2)Se core-shell nanowires was conducted above the softening temperature ( approximately 132 degrees C) of Ag(2)Se. The Ag(2)Se shells in a-Se@Ag(2)Se core-shell colloids were first collapsed and then transformed into isolated solid spheres as the a-Se cores were dissolved in solvent and transformed into separate t-Se nanowires. In t-Se@Ag(2)Se core-shell nanowires, the soft Ag(2)Se shells dewetted on the t-Se nanowires and transformed into small droplets. While the formation of the spherical Ag(2)Se was not affected by the presence of surfactants, the structure of t-Se was highly dependent on the chemical structure of the polymeric surfactants.

Supramolecular Assembly of Single-Source Metal–Chalcogenide Nanocrystal Precursors

“…Coinage metal chalcogenides (Ag 2 E, Cu 2 – x E, where E = S, Se) have been synthesized using hot-injection chemistries typical of quantum dot formation with uniform sizes but do not typically give rise to the formation of anisotropic shapes. For example, Brutchey et al have demonstrated the use of solvent systems such as ionic liquids and thiol–amine mixtures to create metal chalcogenide nanocrystalline products. − Cation and anion exchange have also been used successfully to produce chalcogenide and pnictide nanocrystals. − In the work of Vela et al, the silylative deoxygenation of metal oxides with trimethylsilyl reagents has produced several different nanophases, including heterobimetallic structures . The choice of both metal salt anions and metal–ligand coordination chemistry has been demonstrated to have a profound effect on crystal morphology and surface structures.…”

Morpholine-4-Carbodithioate Se and Te Complex as Single Source Precursor for Synthesis of Se and Te with Diverse Morphologies

“…Diethyldithiocarbamato tellurium(IV) and [(CH 3 ) 4 N] 4 Ge 4 Se 10 have also been used as single source precursors for the formation of tellurium with flower-like morphology and selenium nanowires by Wang et al and Gautam et al, respectively. However, it is desirable to develop more simple routes for the synthesis of Se and Te of diverse morphologies from the same single source precursors under different experimental conditions, which could improve the performance of the existing devices and also act as a good template for the preparation of important functional materials, such as Cu 2 Se, Ag 2 Se, Bi 2 Se 3 , CdSe, CdTe, PbTe, and Nb 3 Te 4 . − …”