Preparation of CdS Nanoparticles from Thiosemicarbazone Complexes: Morphological Influence of Chlorido and Iodido Ligands

Abstract

Cadmium(II) thiosemicarbazone complexes were prepared and characterized by elemental analysis and IR and NMR spectroscopy. The complexes were then investigated as potential single‐source precursors for the synthesis of oleylamine‐capped cadmium sulfide nanoparticles by solvothermal decomposition. The resulting nanomaterials were characterized by powder XRD, TEM, HRTEM, energy‐dispersive X‐ray analysis, and UV/Vis spectroscopy. Peak broadening in the XRD patterns confirmed the presence of relatively small hexagonal CdS nanocrystals. The TEM studies evidenced that the chlorido precursors produced CdS nanostructures whose morphologies differed from those obtained from the iodido precursors. CdS nanoparticles in the form of cubes/spheres/rods and nanodendrite structures were obtained from CdCl2 and CdI2 thiosemicarbazone complexes, respectively. The UV/Vis spectra revealed that the as‐synthesized CdS nanoparticles exhibited a quantum effect due to their sharp band edges, which are blueshifted relative to those of bulk CdS. The size, morphology and shape of the nanoparticles were also shown to depend on the temperature of formation.

The Many “Facets” of Halide Ions in the Chemistry of Colloidal Inorganic Nanocrystals

“…synthesized CdS NCs through the thermolysis of a single-source precursor obtained from CdX 2 –thiosemicarbazone (X = Cl and I) complexes. 258 …”

Room-Temperature Synthesis of ZnS Nanoparticles Using Zinc Xanthates as Molecular Precursors

“…As an example, Liu et al reported on the use of glutathione as both ligand and sulfur source for luminescent CdS NPs with tunable color [21].Thermal decomposition of coordination compounds with S-containing ligands (such as dithiocarbamate, dithiocarbonate (xanthate), trithiocarbonate, thiosemicarbazone, and thiobiuret), which serve as sulfide sources, has already been applied to produce metal sulfide NPs with good crystallinity, narrow size distribution, and tunable dimensions [22][23][24][25]. For instance, a hot-injection route, which uses thermolysis of metal (Zn, Cd, Hg) complexes in alkylamine at 230-280 • C, was shown to lead to formation of monodispersed metal sulfide NPs wrapped with amines [26][27][28][29][30]. Interestingly, aggregates of CdS with sizes of 140-200 nm were obtained from complex Cd(ethylxanthate) 2 , while NPs with diameters of 4-7 nm were formed from diamine-ethylxanthate complex of Cd(II), indicating the protective role of strongly coordinated diamine ligand for the metal center [31].…”

Indium Chalcogenide Nanomaterials in the Forefront of Recent Technological Advancements

“…For example, there is a study which has evaluated the influence of halide ions on the optical properties of CuInS 2 quantum dots [26]. Similar to our work where we evaluated the influence of halide ligands in the single-source precursors on the morphological and optical properties of cadmium sulfide [27,28] and lead sulfide [29] nanoparticles, the authors in this case follow a multiple-source precursor route (through the solvothermal synthetic protocols) using CuX (where X = I, Cl and Br) salts. The optical properties show unique behavior with respect to the metal salt used, attributed to the physicochemical properties resulting from the growth processes which consequently promote accumulation of the halide ions in the crystal lattices of the quantum dots.…”