Papers by Keyword: CdS

Abstract: Bentonite is a commercial name of a clay mineral which consists of montmorillonite as main composition. Montmorillonite is a layered silicate clay mineral in which an alumina octahedral arrangement situated between two tetrahedral of silica sheet. Substitutions of Al³⁺ within the lattice structure of Si⁴⁺ in tetrahedral sheet and Mg²⁺ for Al³⁺ in octahedral sheet resulted unbalanced charge in the structural units of bentonite. The charge imbalanced is compensated by exchangeable cation such as Na⁺, Ca²⁺ and Mg²⁺ in the interlayer spaces. Bentonite has several advantages such as ion exchange property, adsorptive property, swelling behavior and large surface area. [1]

Abstract: Dichloromethane (CH2Cl2) is one of main components of odorous gases from pharmaceutical sewage treatment plants. In this work, firstly the CdS/TiO2 loaded on ACFs composite photocatalysts was prepared. Gaseous CH2Cl2 was selected as the model reactant, the photocatalytic activities of CdS/TiO2/ACFs composites had been investigated. The results showed that the degradation rate of CH2Cl2, when the light was turned on after the CdS/TiO2/ACFs composites were saturated, was significantly higher and could maintain a longer time than that one of direct light. At initial stage, the degradation rate of CH2Cl2 could reach to 94%, while it decreased with the increase of the irradiation distance. It increased with the amount of composites before illumination 70 min; however it becomes reverse after 70 min. The degradation rate of CH2Cl2 decreases with the inlet concentration, when the inlet concentration was 26.5 mg m-3, the photodegradation rate declined about 70 % than that one of 8.5 mg m-3 when light 30 min.

Abstract: In this paper, CdS sample and phosphotungstic acid/CdS composite materials were prepared by hydrothermal synthesis and impregnation method, respectively. These samples were characterized by FT-IR, XRD and TEM. The characteristic peaks of phosphotungstic acid and CdS appeared in IR spectra of phosphotungstic acid /CdS composite samples. Using the degradation of Rhodamine B and Methylene blue solutions as the model reaction, respectively, the photocatalytic degradation performance of CdS, phosphotungstic acid and their composite samples was discussed under the irradiation of UV light or sunlight. The results showed the degradation effect of phosphotungstic acid /CdS to Rhodamine B and Methylene blue solution was better than CdS under the irradiation of 250 W mercury lamp or sunlight. Composite sample 1 had the best photocatalytic activity and its degradation rate on Rhodamine B was 85.2 % at 120 mins with pH 3.5 under sunlight, and the degradation rate of Methylene blue reached about 92.1% at 120 mins with pH 6.0 under sunlight.

Abstract: Nanocrystalline cadmium sulfide (CdS) thin films have been successfully grown onto glass substrate via chemical bath deposition (CBD) technique under microwave irradiation (MWI) as a heating source. Aqueous solutions of cadmium chloride (CdCl₂) and thiourea [SC(NH₂)₂] were used as Cd⁺ and S^- ion sources respectively. In this study, the effect of reactants molar concentration on the deposited thin films thickness and quality were investigated. Higher thickness was obtained for the film prepared with concentration of 10mM whereas; the lowest was for the film prepared using 11mM. Keywords: CdS, nanocrystalline thin films, molar concentration, properties.

Abstract: Three types of hybrid solar cells based on CdS nanowire crystals have been prepared, i.e., (i) nanocrystal - polymer, (ii) nanocrystal - dye and (iii) nanocrystal - organic donor-acceptor bulk heterojunction (BHJ), and the role of CdS layer in each of the above structures has been elucidated. It has been found that CdS plays the active role of acceptor in the first two types of solar cells, whereas it plays the role of an electron-transporting (hole-blocking) layer to rectify electron flow from the organic donor-acceptor BHJ to anode in the case (iii). By changing morphology of the CdS layer from a textured continuous film to a nanowire array we demonstrate an improved efficiency of collection of charge carriers due to the increased organic-CdS interface area. Overall, a bifunctional role of the CdS nanostructured layer as a bottom electrode with a high electron affinity and as a means to increase a hybrid interface for better electron collection from the organic active layer has been demonstrated.

Abstract: Our work is dedicated for review of the synthesis of the new nanocomposite media with Au and CdS nanoparticles. Also formation of filament structure in presented samples as result of interaction with femtosecond laser pulses in depending on the component composition of the samples and the various experimental conditions was investigated.

Abstract: Cadmin sulfate nanoparticles, hollow sphere (CdS-HS) and rode (CdS-NR) were synthesized by ultrasonic and solvothermal process, respectively. The effect of the two kinds of nanoparticles on flammability of polystyrene was investigated using cone calorimeter (Cone) and microscale combustion calorimeter (MCC). Cone data indicate that the incorporation of 1% CdS nanoparticles leads to a about 20% reduction in the peak heat release rate (PHRR) compared to the pure PS; CdS-NR is more efficient in reducing the PHRR proved by both Cone and MCC results. The TG results show that the addition of the nanoparticles mainly increases thermal stability of PS at high temepratures.

Abstract: Cadmium sulfide (CdS) nanostructures were prepared with different spin coating speed 1000 and 3000 rpm and molarities of Cd:S to be 1.2 to 0.01 mol/L using sol-gel spin coating technique. It is found that the average grain size of CdS nanostructures deposited on glass substrates at 1000 and 3000 rpm is 43 to 4 nm respectively. The effect of grain size on the semiconductor properties are in agreement with experimental and theoretical data.

Abstract: CdS has been synthesized electrochemically on multi walled carbon nanotubes paste electrode (MWCNPE) from aqueous solutions consists of Cd²⁺ and S₂O₃^2- at40°C, using potentiostatic technique.Cyclic voltammetric response of thiosulfateand Cd²⁺ individually and together has been investigated. The optimum conditions of CdS electrodeposition were determined. Interesting data were obtained and discussed in this work. The mechanism of CdS electrodeposition was suggested. Moreover, the electrodeposited CdS is of n-type semiconductor. Ithas been investigated by the Mott-Schotky test, and also the concentrations of donors (N_D) were determined.

Abstract: In this paper, we fabricated the CdS nanocrystals film on indium-tin oxide (ITO) glass substrates through one-step solvothermal treatment of cadmium nanocrystals layer and sulfur powder in the presence of absolute ethanol. And then we spin-coated a poly (3-hexylthiophene) (P3HT) layer in the CdS film, and finally evaporated an Au electrode through a shadow mask. The resulting products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscope (AFM). A photovoltaic performance measurement of the fabricated device (ITO/CdS:P3HT/Au) shows a short circuit current density (J_sc) of 0.82 mA cm², and a power conversion efficiency (η) of 0.03% under an illumination of 100 mW/cm².