Contamination-free solutions of selenium in amines for nanoparticle synthesis

Abstract

We present, for the first time, versatile solutions of concentrated selenium, within an array of amines, in a fast and low temperature manner without contaminants. These solutions allow the unprecedented opportunity to synthesize a variety of pure selenium and selenide nanoparticles as well as mixed chalcogen sulfoselenide compounds.

Solution processed As30Se70chalcogenide glass thin films with specular optical quality: multi-component solvent approach

“…The selenium (with Se-Se homopolar bonds) is notoriously insoluble in most common solvents under ambient conditions [32][33][34] and XPS measurements of As30Se70 bulk glass have confirmed, that nearly 70% of Se atoms are present in form of Se-Se-As or Se-Se-Se fragments [35]. The elemental selenium and compounds of selenium with 15. group elements can be dissolved at room temperature and ambient pressure in solution formed by mixing amines with thiols [33,34,36]. The thiols are responsible for cleavage of Se-Se bonds and the amines actively participate in stabilization of Se ions (probably by hydrogen bonding).…”

“…2, red line). The deposited thin films would be also contaminated with disulfides which are formed from thiols as a part of proposed dissolution mechanism [33]. To overcome the possible sulfur contamination and to increase the optical quality of deposited thin films, we have replaced the 10 vol.…”

MoxW1−x(SySe1−y)2 Alloy Nanoflakes for High‐Performance Electrocatalytic Hydrogen Evolution

“…25 different alloy nanoflakes having a general formula of Mo x W 1− x (S y Se 1− y ) 2 (where x , y = 0, 0.33, 0.5, 0.67 or 1) were synthesized using an established high‐temperature solution method by reacting the calculated amounts of MoCl 5 and/or WCl 6 with S and/or Se powders in a mixed solvent of oleylamine and 1‐octadecene at 300 °C under N 2 atmosphere (see the Experimental for details) . Oleylamine was chosen as the solvent for its appreciable solubility toward both S and Se powders, forming oleylammonium polysulfide or polyselenide, respectively . Upon heating, these compounds decomposed, and liberated H 2 S or H 2 Se to react with Mo and/or W precursors in solution.…”

“…[ 16,18 ] Oleylamine was chosen as the solvent for its appreciable solubility toward both S and Se powders, forming oleylammonium polysulfi de or polyselenide, respectively. [ 21,22 ] Upon heating, these compounds decomposed, and liberated H 2 S or H 2 Se to react with Mo and/or W precursors in solution. The process was evidenced by the immediate solution color change and the formation of black solids.…”

Phase transition in Cu2+xSnS3+y(0 ≤x≤ 2; 0 ≤y≤ 1) ternary systems synthesized from complexes of coumarin derived thiocarbamate motifs: optical and morphological properties

“…The compounds with Cu exclusively in the 1+ oxidation state (Cu 4 SnS 4 , Cu 2 SnS 3 ) are expected to be better solar absorbers than those with Cu in a mixed 1+/2+ oxidation state, as the multi-valency of Cu can lead to high carrier concentrations ($10 22 cm À3 ) or hole selftrapping. [30][31][32][33][34][35][36] The effect of variation of Cu/Sn ratio on the morphology of CTS NPs in OLA at 200 C can be seen in Fig. 5c, smaller monodispersed nanocubes were produced which averaged 9.87 AE 1.71 nm (n ¼ 25).…”