Cadmium Diethyldithiocarbamate Research Articles

Construction of a stable fluorescent sensor based on CsPbBr3/CdS core/shell quantum dots for selective and sensitive detection of tetracycline in ethanol.

The weakly bound organic ligand shells around perovskite quantum dots (QDs) are easily decomposed and cannot provide sufficient stability in polar solvents, which greatly obstructs their applications in sensing. Herein, a fluorescent sensor based on CsPbBr3/CdS core/shell QDs was developed for the detection of tetracycline (TC) in the polar solvent-ethanol. Pristine CsPbBr3 QDs were treated with cadmium diethyldithiocarbamate (Cd(DDTC)2) to form a shell on the surface at 110 °C, while extra oleylammonium bromide (OAmBr) was added to inhibit the phase transformation of CsPbBr3 into a Cs4PbBr6 impurity phase during high-temperature processing. And finally CsPbBr3/CdS core/shell QDs were successfully synthesized. The capping with the CdS inorganic shell remediated surface defects and improved the stability in ethanol without affecting the emission properties of the parent CsPbBr3 QDs. The results showed that the fluorescent sensor detected TC in the range of 0.05-25 μM with a low detection limit of 22.6 nM, whereas it had high selectivity and anti-interference ability for TC. And the fluorescence quenching mechanism of the sensor was mainly photoinduced electron transfer between TC and CsPbBr3/CdS QDs. Our research provides a unique way to improve the stability of perovskite QDs in polar solvents and applications in fluorescence detection.

Formation and characterization of ZnS and CdZnS films using open-air chemical vapor deposition for buffer layers of compound semiconductor solar cells

ZnS and CdZnS (a mixed crystal phase of ZnS and CdS) were formed using the open-air CVD method. Cadmium diethyldithiocarbamate (C10H20CdN2S4) and zinc diethyldithiocarbamate (C10H20ZnN2S4) were used as the source materials for CdS and ZnS, respectively. By changing the ratio of source materials, it was found that the bandgap and the lattice constant of the CdZnS film were continuously changing without a miscibility gap. Furthermore, the bandgap of the obtained ZnS films was less than the reported bandgap of ZnS (3.68 eV) due to incorporation of oxygen. X-ray diffraction analysis revealed that the increase of Zn in CdZnS film generated a crystalline disorder. When the substrate temperature was changed from 421 °C to 464 °C, the deposition rate increased fourfold for the CdS and ZnS films. The impact of substrate temperature on the bandgap and lattice constant was found to be less pronounced.

Single-precursor synthesis of sub-10 nm CdS nanoparticles embedded on graphene sheets nanocatalyst for active photodegradation under visible light

Quantum dots (QDs) sized sub-10 nanometer (nm) cadmium sulfide (CdS) nanoparticles (NPs) embedded graphene sheets photocatalyst expected significant interest owing to their tunable band gap and high surface to volume ratio. Here demonstrate a single source precursor cadmium diethyldithiocarbamate (Cd[DTC]2) used in presence of reduced graphene oxide (RGO) as template to synthesis sub-10 nm CdS NPs embedded graphene sheet by thermal decomposition method under optimized experimental conditions. The resulting CdS sub-10 NPs modified RGO was characterized with various analytical methods including XRD, HRTEM, UV, FTIR, Raman, XPS, SEM and EDX with mapping. The incorporation of sub-10 CdS NPs uniformly loaded on both sides of RGO was observed by HRTEM micrographs. The photocatalytic performance of the CdS/RGO was studied using a standard textile dye methylene blue (MB) under direct sun light exposure. The results proved that CdS/RGO catalyst exhibit an enhanced degradation rate than the pure CdS NPs. Electrochemical impedance spectroscopic method was employed to examine the prepared CdS/RGO nanocomposites. Results illustrate to CdS species on the surface of RGO can efficiently hasten the separation and postponed the recombination rate in transfer of photo-excited charge carriers. Also, sub-10 CdS/RGO nanocomposites have high surface area and the present method can be used for the preparation of CdS/RGO in large scale.

Colloidal branched CdSe/CdS ‘nanospiders’ with 2D/1D heterostructure

In this paper we report the synthesis of colloidal CdSe/CdS core–shell heteronanoplatelets with epitaxially grown wurtzite (WZ) 1D CdS branches or legs by using cadmium diethyldithiocarbamate as a single-source precursor. The growth of WZ branches was achieved by exploiting zinc blende-wurtzite polytypism of cadmium chalcogenides induced by oleylamine. Synthesized ‘nanospiders’ exhibit enhanced absorption in the UV-blue region and narrow and relatively intense red photoluminescence depending on the amount of CdS in the heteronanostructure.

Characteristics of nanocrystalline thin films of cadmium sulphide deposited at the water-oil interface

Thin films of nanocrystalline CdS were obtained at the water-toluene interface by reacting cadmium diethyldithiocarbamate in toluene with aq. Na2S. Three parameters unique to the topical deposition scheme: the effect of column heights, stirring and the action of molecular surfactants are systematically investigated. The obtained nanocrystalline aggregates are characterized by scanning- and transmission electron microscopy, X-ray diffraction and profilometric measurements. Conditions for obtaining smooth device quality thin films have been identified during these experiments.

Fluorecence Microscopy Study of CdS quantum dots Obtained by Laser Irradiation from a Single Source Precursor in Polymeric Film

Recently the quantum dots (QDs) synthesis from single source precursors (SSPs) showed a potential interest for patterning formation of nano-composites. In this approach the SSPs have to be mixed with a matrix that afterwards is treated selectively to obtain the desired nanocomposite. The study of the generation of the QDs from the SSPs is, therefore, crucial for the definition of its behaviour within the polymeric matrix.The formation of the CdS QDs via thermolysis of the cadmium diethyldithiocarbamate (CdDDTC) was performed and studied in the presence of a non coordinating solvent such as octadecene (ODE) in presence of myristic acid (MA) as ligand.The precursor is then studied in combination with the poly(methyl methacrylate) (PMMA) polymer for the generation of the CdS QDs under the laser irradiation within a film. The effect of the laser has been studied both on neat PMMA and on the polymer/precursor blend film with the aid of the fluorescence microscope.The results are used to identify the optimal laser parameters to obtain the decomposition of the precursor and to evaluate the effect of the laser irradiation on the polymer.

Synthesis and structural characterization of magnetic cadmium sulfide–cobalt ferrite nanocomposite, and study of its activity for dyes degradation under ultrasound

Cadmium sulfide–cobalt ferrite (CdS/CFO) nanocomposite was easily synthesized by one-step hydrothermal decomposition of cadmium diethyldithiocarbamate complex on the CoFe2O4 nanoparticles at 200 °C. Spectroscopic techniques of powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), UV–visible spectroscopy, field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET), and magnetic measurements were applied for characterizing the structure and morphology of the product. The results of FT-IR, XRD and EDX indicated that the CdS/CFO was highly pure. SEM and TEM results revealed that the CdS/CFO nanocomposite was formed from nearly uniform and sphere-like nanoparticles with the size of approximately 20 nm. The UV–vis absorption spectrum of the CdS/CFO nanocomposite showed the band gap of 2.21 eV, which made it suitable for sono-/photo catalytic purposes. By using the obtained CdS/CFO nanocomposite, an ultrasound-assisted advanced oxidation process (AOP) has been developed for catalytic degradation of methylene blue (MB), Rhodamine B (RhB), and methyl orange (MO)) in the presence of H2O2 as a green oxidant. CdS/CFO nanocomposite exhibited excellent sonocatalytic activity, so that, dyes were completely degraded in less than 10 min. The influences of crucial factors such as the H2O2 amount and catalyst dosage on the degradation efficiency were evaluated. The as-prepared CdS/CFO nanocomposite exhibited higher catalytic activity than pure CdS nanoparticles. Moreover, the magnetic property of CoFe2O4 made the nanocomposite recyclable.

Efficient Photocatalytic Hydrogen Generation from Ni Nanoparticle Decorated CdS Nanosheets

High-quality, thickness-controlled CdS nanosheets (NSs) have been obtained through the thermal decomposition of cadmium diethyldithiocarbamate in octadecene. Ensembles with discrete thicknesses of 1.50, 1.80, and 2.16 nm have been made with corresponding lateral dimensions on the order of 90 nm × 20 nm. These latter values make the 1–3 nm NSs the largest 2D CdS specimens made to date using colloidal chemistry. Associated Ni nanoparticle decorated counterparts have been made through the photodeposition of Ni onto NSs with an average nanoparticle diameter of 6 nm. Subsequent photocatalytic hydrogen generation measurements have compared the performance of CdS NSs with that of their Ni NP decorated counterparts in water/ethanol mixtures. Apparent quantum yields as large as 25% have been seen for Ni NP decorated NSs with transient yields as large as 64% within the first 2 h of irradiation. Results from ensemble femtosecond transient differential absorption spectroscopy reveal that the origin of this high efficiency stems from efficient electron transfer from CdS to Ni. In this regard, the CdS/Ni semiconductor/metal heterojunction acts to dissociate strongly bound excitons in CdS NSs, creating free carriers needed to carry out relevant reduction chemistries.

Microwave‐assistant route to hybrid semiconductor nanocrystals with quasi solution‐solid‐solid mechanism

A facile microwave‐assistant route was developed for the synthesis of hybrid nanocrystals. Colloidal hybrid nanocrystals, Ag2S‐CdS, were prepared by using Ag2S nanocrystals and cadmium diethyldithiocarbamate as raw materials under microwave irradiation. The fast ion conductor, Ag2S nanocrystal, catalyzes the growth of CdS nano‐building blocks through a quasi solution‐solid‐solid mechanism. The ultraviolet‐visible absorption and photoluminescence spectra of the Ag2S‐CdS hybrid nanocrystals were investigated. One of the main advantages for this synthesis is the efficiency of dramatically reducing overall processing time. This report provides a new route for the growth of semiconductor hybrid nanocrystals based on Ag2S and may be extended to the preparation of other hybrid colloidal nanostructures.

Synthesis of Spherical CdS Quantum Dots Using Cadmium Diethyldithiocarbamate as Single Source Precursor in Olive Oil Medium

A rapid synthesis route for the preparation of spherical cadmium sulfide (CdS) nanoparticles (NPs) was demonstrated by thermal decomposition of cadmium diethyldithiocarbamate(Cd[Ddtc]2) metal complex in the presence of a catalytic amount of hexadecylamine (HDA) using olive oil as the reaction medium. CdS nanoparticles were isolated and characterized by using HRTEM, FESEM, TGA, XRD, EDAX, PL, and Raman studies. The photocatalytic behaviour of the CdS nanoparticles was analyzed against the textile dye Congo red (CR). The degradation process follows the pseudo first order kinetics and the proposed method can be utilized for the efficient degradation of Congo red textile dye using UV light irradiation. Keywords: CdS nanoparticles, Congo red, Photodegradation, Thermal decomposition.

Binding forms of gold(III) from solutions by cadmium diethyl dithiocarbamate: Thermal behavior and role of secondary interactions in the supramolecular self-assembly of polymeric complexes ([Au{S2CN(C2H5)2}2][AuCl4]) n and [Au{S2CN(C2H5)2}Cl2] n

The chemisorption interaction between the binuclear cadmium diethyl dithiocarbamate (EDtc), [Cd2{S2CN(C2H5)2}4], (chemisorbent I) and AuCl3 solutions in 2 M HCl results in the formation of polymeric gold(III) complexes: ([Au{S2CN(C2H5)2}2][AuCl4]) n (II) and [Au{S2CN(C2H5)2}Cl2] n (III) with the same Au : EDtc : Cl ratio (1 : 1 : 2). The alternating centrosymmetric cations and anions of complex II are structurally self-assembled to form linear polymeric chains: the gold atom in [Au{S2CN(C2H5)2}2]+ forms secondary Au(1)⋯Cl(1) bonds (3.7784 A) with two neighboring [AuCl4]− anions. This binding is additionally strengthened by secondary S(1)⋯Cl(1) interactions (3.4993 A). The mixed-ligand complex III comprises two structurally non-equivalent molecules [Au{S2CN(C2H5)2}Cl2]: A—Au(1) and B—Au(2), each being in contact with two nearest neighbors through pairs of unsymmetrical secondary bonds: Au(1)⋯S(1)a/b 3.4361/3.6329; and Au(2)⋯S(4)c/d 3.4340/3.6398 A. At the supramolecular level, this gives rise to independent zigzag-like polymeric chains, (⋯A⋯A⋯A⋯) n and (⋯B⋯B⋯B⋯) n along which antiparallel isomeric molecules of III alternate. The chemisorption capacity of cadmium diethyl dithiocarbamate calculated from the gold(III) binding reaction is 963.2 mg of gold per 1 g of the sorbent. The recovery conditions for the bound gold were elucidated by simultaneous thermal analysis of II and III. The DSC curves reflect different sets of heat effects, because thermolysis occurs for complex molecules (III) or for cations and anions (II). Nevertheless, the patterns of experimental TG curves are similar despite different structures of the complexes. The final product of thermal transformations is reduced gold.

Phase transitions at high pressure in the donor–acceptor complexes of C 60 studied by Raman spectroscopy

In this study, the Raman spectra of the molecular donor–acceptor complex {Cd(dedtc)2}C60 (fullerene with cadmium diethyldithiocarbamate) were measured at pressure of up to 8 GPa. The phonon modes of the C60 molecule dominate in the Raman spectra, whereas the molecular donor modes are absent probably due to the small cross-section of Raman scattering. The Raman peaks split and soften near 2.5 GPa, indicating the phase transition associated with the inter-fullerene covalent bonding. The high pressure phase is stable as the pressure increases up to ∼8 GPa, while with decreasing pressure it reverts to the initial monomer phase near 2 GPa.

Crystal Structure Control of Zinc-Blende CdSe/CdS Core/Shell Nanocrystals: Synthesis and Structure-Dependent Optical Properties

Nearly monodisperse zinc-blende CdSe/CdS core/shell nanocrystals were synthesized by epitaxial growth of 1-6 monolayers of CdS shell onto presynthesized zinc-blende CdSe core nanocrystals in one pot. To retain the zinc-blende structure, the reaction temperature was lowered to the 100-140 °C range by using cadmium diethyldithiocarbamate as a single-source precursor and primary amine as activation reagents for the precursor. Although the wurtzite counterparts grown under the same conditions showed optical properties similar to those reported in the literature, zinc-blende CdSe/CdS core/shell nanocrystals demonstrated surprisingly different optical properties, with ensemble single-exponential photoluminescence decay, significant decrease of photoluminescence peak width by the shell growth, and comparatively high photoluminescence quantum yields. The lifetime for the single-exponential ensemble photoluminescence decay of zinc-blende CdSe/CdS core/shell nanocrystals with 3-4 monolayers of CdS shell was reproducibly found to be approximately 16.5 ± 1.0 ns.

Effect of the Cooling Rate on Dimerization of C60•– in Fullerene Salt (DMI+)2·(C60•–)·{Cd(Et2NCS2)2I–}

The salt (DMI(+))(2)·(C(60)(•-))·{Cd(Et(2)NCS(2))(2)I(-)} (1) containing fullerene radical anions, the anions of cadmium diethyldithiocarbamate iodide, and N,N'-dimethylimidazolium cations was obtained. Fullerenes are monomeric in 1 at 250 K and form three-dimensional packing in which each fullerene has nearly tetrahedral surroundings from neighboring fullerenes. Fullerenes with a shorter interfullerene center-to-center distance of 10.031(2) Å form spiral chains arranged along the lattice c axis. The convolution consists of four fullerene molecules. Dimerization realized in 1 within the spiral chains below 135 K manifests a strong dependence on the cooling rate. The "frozen" monomeric phase was obtained upon instant quenching of 1. This phase is stable below 95 K for a long time but slowly converted to the dimeric phase at T > 95 K. It exhibits a weak antiferromagnetic interaction of spins below 95 K (the Weiss temperature is -4 K), which results in the splitting of the electron paramagnetic resonance (EPR) signal into two components below 10 K. A disordered phase containing both C(60)(•-) monomers and singly bonded (C(60)(-))(2) dimers with approximately 0.5/0.5 occupancies is formed at an intermediate cooling rate (for 20 min). The position of each fullerene in this phase is split into three positions slightly shifted relative to each other. The central position corresponds to nonbonded fullerenes with interfullerene center-to-center distances of 9.94-10.00 Å. Two other positions are coincided to dimeric fullerenes formed with the right and left fullerene neighbors within the spiral chain. This intermediate phase is paramagnetic with nearly zero Weiss temperature due to isolation of C(60)(•-) by diamagnetic species and exhibits a strongly asymmetric EPR signal below 20 K. A diamagnetic phase containing ordered singly bonded (C(60)(-))(2) dimers can be obtained only upon slow cooling of the crystal for 6 h.

Ionic liquid-assisted synthesis, structural characterization, and photocatalytic performance of CdS nanocrystals

With the assistance of the ionic liquid trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentylphosphinate), we have successfully synthesized short nanorods, quasi-nanospheres and faceted CdS nanoparticles via thermal decomposition of cadmium diethyldithiocarbamate complexes. It was shown that the shape, size and crystallinity of the products could be controlled through delicate regulation of the reaction temperature, monomer concentration, reaction time, and ionic liquid ratio. We found that higher temperature was beneficial to the good crystallinity, while the lower temperature and higher monomer concentration were in favor of anisotropic structures. The used ionic liquid contributed to the formation of hexagonal phase CdS nanocrystals, and its ratio played an important role in determining the ultimate morphology of products. The possible mechanism for the formation CdS nanocrystals was proposed. Furthermore, the as-prepared CdS samples demonstrated a highly photocatalytic activity in the degradation of methyl orange under visible light irradiation.

Easy synthesis of luminescent CdS nanocrystals using a biphasic oil–water system

Nanocrystals of CdS were synthesized by a facile new method employing cadmium diethyldithiocarbamate in toluene and aqueous thioacetamide at temperatures between 35 and 70 °C. Unusually for particulates synthesized at such low temperatures, strong size-tunable band edge luminescence is observed. The diameters of the nanocrystals and the position of emission maximum could be varied by changing the reaction time and temperature. The nanocrystals were charecterized by transmission electron microscopy, X-ray diffraction, absorption and emission spectroscopies.

Single-source precursor route for overcoating CdS and ZnS shells around CdSe core nanocrystals

We reported a facile route for overcoating CdS and ZnS shells around colloidal CdSe core nanocrystals. To synthesize such double shelled core/shell nanocrystals, first, CdSe core nanocrystals were prepared in a much “greener” and cheap route, which did not involve the use of hazardous and expensive trioctylphosphine. Then, a low-cost and labor-saving route was adopted for the CdS and ZnS shell growth with the use of thermal decomposition of commercial available air stable single-source precursors cadmium diethyldithio-carbamate and zinc diethyldithiocarbamate in a non-coordinating solvent at intermediate temperatures. Powder X-ray diffraction patterns and transmission electron microscopy images confirm the epitaxial growth of the shell in the core/shell nanocrystals. The photoluminescence quantum yield of the resulting CdSe/CdS/ZnS core/shell nanocrystals can be as high as 90% in organic media and up to 60% after phase transfer into aqueous media. By varying the size of CdSe cores, the emission wavelength of the obtained core/shell nanostructures can span from 554 to 636 nm.

Total Spontaneous Resolution of Five‐Coordinate Complexes

Talking about a resolution: Bulk quantities of five-coordinate complexes have been resolved for the first time using zinc and cadmium diethyldithiocarbamate species. The stereochemical outcome can be controlled by seeding with the desired isomer, giving access to either enantiomer in high enantiomeric excess and yield.

Fungicidal and bactericidal activity of metal diethyldithiocarbamate fungicides

Copper diethyldithiocarbamate, cadmium diethyldithiocarbamate, lead diethyldithiocarbamate, nickel diethyldithiocarbamate and zinc diethyldithiocarbamate have been synthesized. They have been characterized using TG, DTA, IR spectroscopy, X-ray and atomic absorption spectrophotometry. The thermal conversion of the compounds is 54.36–88% at 1000°C. Their solubility in sodium hydroxide, mineral acids, organic solvents, distilled water and salts solution has been measured. Fungicidal activity of the dithiocarbamates has been tested by well or cup diffusion method using five fungi species. Their activity has also been tested by broth dilution method using six bacterial species. Minimum Inhibitory Concentration (bactericidal) is 6.25–25.00 μg mL−1.

Uptake of Neutral Metal Complexes by a Green Alga: Influence of pH and Humic Substances

We have examined the influence of pH and a natural humic acid on the short-term uptake (<40 min) of a neutral, lipophilic metal complex by a unicellular freshwater alga, Pseudokirchneriella subcapitata. Cadmium diethyldithiocarbamate ([Cd(DDC)2]0) was used as a model lipophilic metal complex and Suwannee River Humic Acid (SRHA) was chosen as a representative aquatic humic acid (6.5 mg C L−1). Under the experimental conditions virtually all the Cd was expected to be present as the lipophilic complex ([Cd]T = 0.38 nM; [DDC] 1 μM; [Cd2+] <10−15 M; pH 7.0, 6.0, or 5.5). Uptake of [Cd(DDC)2]0 proved to be sensitive to pH changes. It was lower at pH 6.0 and 5.5 than at pH 7.0. To our knowledge, this is the first demonstration of reduced uptake of a lipophilic metal complex at low pH. The presence of SRHA also affected uptake, either by binding the lipophilic complex in solution and reducing its bioavailability (pH 7.0) or by increasing the permeability of the algal membrane (pH 5.5).