Influence Of Copper Concentration Research Articles

Physical and optical properties of sprayed Cu2ZnSnS4 (CZTS) thin film: effect of Cu concentration

The crystallographic microstructural and optical properties of CZTS thin film have been investigated with influence of copper concentration in spray solution. The X-ray and Raman study carried out to the prepared CZTS thin films and attained pure kesterite phase. The results of microstructural properties such as crystallite size, d-spacing, microstrain, texture coefficient and standard deviation investigated. The prepared CZTS thin film shows very high optical absorption of the order of 105 cm−1 in the visible region and the optical band gap energy varied between 1.45 and 1.47 eV. This optical band gap tuning is most applicable for solar cells. By using the Wemple–DiDomenico (WDD) single oscillator model, the optical parameters were calculated such as single oscillator energy (E0), dispersion energy (Ed), static refractive index (n0), etc. Large values of optical conductivity (σ) give the promise to the solar cell application.

Structural properties of CuxNi1-xFe2O4 nano ferrites prepared by urea-gel microwave auto combustion method

ABSTRACTCopper-substituted nickel ferrite nanoparticles were prepared via a sol-gel route using urea as a chelating agent. The influence of copper concentration on the microstructure, crystal structure of copper-substituted nickel ferrite nanoparticles has been studied. The results indicate that the substitution of copper influences strongly the microstructure, crystal structure and particle diameter. Powder XRD confirmed single phase cubic structure. Morphology of the particles were studied and particle size was confirmed using SEM. Magnetic properties were studied using VSM method. The dielectric constant and the dielectric loss were increased as the temperature increased at a constant frequency. Dielectric constant (έ) is determined by measuring capacitance (C). Variations of dielectric constant (έ) with frequency as well as temperature have been studied.

Extensive Literature Search on the ‘Effects of Copper intake levels in the gut microbiota profile of target animals, in particular piglets’

Extensive Literature Search on the ‘Effects of Copper intake levels in the gut microbiota profile of target animals, in particular piglets’

Influence of Copper Concentration on the Structural and Optical Properties of Chemically Deposited CuSbS2 Thin Films

Thin films of CuSbS2 have been deposited on ultrasonically cleaned glass substrates using a simple chemical bath deposition technique. Prepared films have been characterized using X-ray diffraction, Field Emission Scanning Electron Microscopy and UV-Vis-NIR spectroscopic techniques, respectively. X-ray diffraction analysis revealed that the prepared films possess polycrystalline in nature with orthorhombic CuSbS2 in addition to secondary phase of monoclinic Cu3SbS3 and cubic Cu12Sb4S13 for different copper concentrations. Field Emission Scanning Electron Spectroscopic analysis showed that the prepared films possess spherical shaped grains with irregular shaped clusters. Optical absorption analysis showed that the prepared films possess band gap value in the range between 1.7 and 2.4 eV.

Influence of copper concentration on the opto-structural, morphological and electrical properties of novel MoSb2−xCuxSe2 thin films

In this work, MoSb2−xCuxSe2 nanocrystalline thin films obtained for different copper concentrations (0.1, 0.2 and 0.3M) on glass substrates by simple chemical bath deposition (CBD) method at room temperature. X-ray diffraction (XRD) patterns revealed the incorporation of copper content by the conversion of orthorhombic Sb2Se3 into orthorhombic Cu3SbSe3 with shift to higher angles. Average crystallite was found to be 24, 36 and 39nm for the deposited films. FESEM analysis indicates that morphological transition from spherical grains with cylindrical nanorods to porous nanofibers for 0.3M and HRTEM confirms the FESEM results with an average grain size of 200nm for 0.1M Cu concentration. EDS analysis confirmed the formation of MoSb2−xCuxSe2 thin films. Current–Voltage (I–V) measurements clearly depicted the ohmic nature of the material in the entire region. Thickness of the films was found to be increased with increase in copper content. The band gap energy (Eg) of the film is in the range of 1.644–3.757eV.

Influence of copper concentration on sprayed CZTS thin films deposited at high temperature

In this study, Cu2ZnSnS4 (CZTS) thin films were deposited by spray pyrolysis technique at constant substrate temperature. The effects of the copper concentration on the structural, morphological and optical properties of the films were investigated. The copper concentration was varied from 0.15 to 0.25M in the steps of 0.05M. The structural studies revealed that the Cu poor film shows low intense peaks, but as Cu concentration increases a relatively more intense and sharper diffraction peaks (112), (200), (220), and (312) of the kesterite crystal structure were observed. Raman spectroscopy analysis confirmed the formation of phase-pure CZTS films. From the morphological studies, it is found that the grain size increased as the Cu concentration increases from 0.15 to 0.25M. The optical band-gap values were estimated to be 1.61, 1.52 and 1.45eV for copper concentration 0.15, 0.20 and 0.25M, respectively. Photoelectrochemical cells using films of different copper concentrations were fabricated and the best cell exhibited an efficiency of 1.09% for 0.25M of copper concentration.

Improved photoelectrochemical performance of Cu2ZnSnS4 (CZTS) thin films prepared using modified successive ionic layer adsorption and reaction (SILAR) sequence

A promising successive ionic layer adsorption and reaction (SILAR) method with a modified sequence has been designed and developed to deposit CZTS thin films with high absorbing characteristics. The influence of copper concentration in the precursor solution on the structural, compositional, morphological and optical properties and on the photoelectrochemical performance of the CZTS thin films has been investigated. The copper concentration in the precursor solution was varied from 0.02 to 0.008M in 0.004M intervals with constant Zn/Sn ratio. The films deposited using the optimized copper concentration of 0.012M exhibit a prominent CZTS phase with a Cu-poor and Zn-rich composition, a dense microstructure and optical band gap energy of 1.43eV. The device based on a Cu-poor (0.012M) CZTS absorber layer exhibits the highest current density of 15.23mA/cm2 with a power conversion efficiency of 3.81%.

Leaf‐like copper oxide nanocrystals synthesized by a gas‐liquid diffusion method at room temperature

The leaf‐like copper oxide (CuO) nanocrystals have been synthesized by a gas‐liquid diffusion method in pure aqueous solution at room temperature. The structure, morphologies and related properties of the as‐prepared crystals were characterized with X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), selected area electron diffraction (SAED) and thermogravimetric analysis (TG). The influence of copper concentration was investigated, which plays an important role in the formation of nanostructured CuO crystals. Only when the copper concentration was low enough (0.005 M) that the leaf‐like CuO could be obtained directly. Additionally, a growth mechanism of CuO was also proposed based on the observed results.

Influence of copper concentration in solutions on the growth mechanism and performance of electrodeposited Cu(In,Al)Se2 solar cells

We conducted a chronoamperometric study to observe the electrochemical behaviors of the nucleation mechanism of electrodeposited Cu(In,Al)Se2 films. A change from instantaneous nucleation to progressive nucleation was observed by increasing the copper concentration. SEM and EDS analyses demonstrated that the surface morphologies and chemical compositions of precursor and post-annealed Cu(In,Al)Se2 films were influenced by the nucleation mechanism. They exhibited that Cu(In,Al)Se2 films had roughly cauliflower-like and triangular structures with Cu-poor composition at the instantaneous nucleation mechanism, whereas smooth and round structures with Cu-rich composition at the progressive nucleation mechanism. Additionally, the quality, growth orientation, composition phase, and optical energy band gap of Cu(In,Al)Se2 films were examined using X-ray diffraction (XRD) patterns, Raman spectra, and (αhν)2 vs. hν plots (UV–vis). Thereafter, the performances of rudimentary Cu(In,Al)Se2 solar cells fabricated at various copper concentrations were discussed, the conversion efficiency of electrodeposited Cu(In,Al)Se2 solar cells were unpublished in previous literatures. Our studies demonstrated that the performances of Cu(In,Al)Se2 solar cells were significantly related to the surface morphology and composition of Cu(In,Al)Se2 absorber layer. The highest conversion efficiency of Cu(In,Al)Se2 solar cells fabricated at a 2-mM copper concentration was 1.96% with open-circuit voltage, short-circuit current, fill factor, Rsh and Rs values of 0.189V, 29.21mA/cm2, 35.4%, 125Ω and 2.82Ω, respectively.

Influence of electron donors and copper concentration on geochemical and mineralogical processes under conditions of biological sulphate reduction

Abstract Sulphidogenous microorganism communities were isolated from soil polluted by crude oil. The study was focused on determining the influence of 1) copper (II) concentration on the activity of selected microorganism communities and 2) the applied electron donor on the course and evolution of mineral-forming processes under conditions favouring growth of sulphate-reducing bacteria (SRB). The influence of copper concentration on the activity of selected microorganism communities and the type of mineral phases formed was determined during experiments in which copper (II) chloride at concentrations of 0.1, 0.2, 0.5 and 0.7 g/L was added to SRB cultures. The experiments were performed in two variants: with ethanol (4 g/L) or lactate (4 g/L) as the sole carbon source. In order to determine the taxonomic composition of the selected microorganism communities, the 16S rRNA method was used. Results of this analysis confirmed the presence of Desulfovibrio, Desulfohalobium, Desulfotalea, Thermotoga, Solibacter, Gramella, Anaeromyxobacter and Myxococcus sp. in the stationary cultures. The post-culture sediments contained covelline (CuS) and digenite (Cu9S5 ). Based on the results, it can be stated that the type of carbon source applied during incubation plays a crucial role in determining the mineral composition of the post-culture sediments. Thus, regardless of the amount of copper ion introduced to a culture with lactate as the sole carbon source, no copper sulphide was observed in the post-culture sediments. Cultures with ethanol as the sole carbon source, on the other hand, yielded covelline or digenite in all post-culture sediments.

Sol-Gel Synthesized Copper-Substituted Cobalt Ferrite Nanoparticles for Biomedical Applications

Copper-substituted cobalt ferrite nanoparticles were prepared via a sol-gel route using citric acid as a chelating agent. The influence of copper concentration on the microstructure, crystal structure and antibacterial property of copper-substituted cobalt ferrite nanoparticles against E. coli and S. aureus has been systematically investigated. The results indicate that the substitution of copper influences strongly the microstructure, crystal structure, particle diameter and antibacterial property of cobalt ferrite nanoparticles.

Sol-Gel Synthesized Copper-Substituted Cobalt Ferrite Nanoparticles for Biomedical Applications

Copper-substituted cobalt ferrite nanoparticles were prepared via a sol-gel route using citric acid as a chelating agent. The influence of copper concentration on the microstructure, crystal structure and antibacterial property of copper-substituted cobalt ferrite nanoparticles against E. coli and S. aureus has been systematically investigated. The results indicate that the substitution of copper influences strongly the microstructure, crystal structure, particle diameter and antibacterial property of cobalt ferrite nanoparticles.

ENGINEERING OF THE SENSITIVE ELEMENTS FOR THE SENSORS OF ETHANOL VAPOR, AMMONIA AND ACETONE BASED ON ZnO:Cu ТHIN FILMS

The ZnO:Cu thin films with different concentrations of copper were obtained by RFmagnetron sputtering technique. Influence of copper concentration on the sensors properties of zinc oxide thin films, such as sensitivity and response time, has been examined for analysis of ethyl alcohol vapor, ammonia and acetone.

The influence of copper concentration and source on ileal microbiota

Copper is normally supplemented in poultry diets as a growth promotant and antimicrobial. However, there are conflicting reports about the growth benefits and little information about how Cu affects the microbiota in the intestinal tract of poultry. Therefore, in vitro and in vivo experiments were conducted with broilers to determine the effects of Cu source and supplementation on ileal microbiota. The influence of Cu on growth of lactobacilli and Escherichia coli in media inoculated with ileal contents was determined in the first study. When Cu sulfate pentahydrate was supplemented to the cultures, quadratic increases in lactobacilli to graded concentrations of Cu up to 125 mg/kg and quadratic decreases in E. coli up to 250 mg/kg of Cu were observed after 24 h of incubation at 37°C. However, when tribasic Cu chloride (TBCC) was supplemented, neither linear nor quadratic responses to graded concentrations of dietary Cu were observed on number of lactobacilli or number of E. coli. The effects of Cu and Cu source on ileal microbiota and growth performance in broiler chickens were determined in the second study. Bird performance was not affected by Cu source or concentration. The bacterial culture enumeration results revealed that supplementation with 187.5 mg/kg of Cu from Cu sulfate pentahydrate and TBCC had no effect on number of ileal lactobacilli of birds. The denaturing gradient gel electrophoresis analyses of ileal microbial communities revealed that neither Cu supplementation nor source had effects on the number of bacterial species predominant in the ileal digesta or associated with the ileal mucosa. Supplementation with TBCC supplementation significantly increased the similarity coefficients of microbiota in the ileal mucosa compared with cross-products of all individuals. This suggests that TBCC may alter the intestinal microbiota, yet this shift had no effect on bird performance.

Influence of absorber copper concentration on the Cu(In,Ga)Se 2/(PVD)In 2S 3 and Cu(In,Ga)Se 2/(CBD)CdS based solar cells performance

The present contribution deals with the influence of the copper concentration in Cu(In,Ga)Se 2 (CIGSe) on the solar cells based on CIGSe/(PVD)In 2S 3 and CIGSe/(CBD)CdS. We find that, depending on the buffer layer, the optimum open circuit voltage (Voc) is not reached for the same copper concentration. The values of Voc for the CIGSe/(CBD)CdS solar cells are higher when the copper content is very close to stoichiometry (25%), whereas, the Voc values for CIGSe/(PVD)In 2S 3 solar cells attain their maximum for lower copper contents. On the other hand, contrary to the case of the (CBD)CdS buffer, the Jsc is strongly hindered for the (PVD)In 2S 3 buffered cells when the copper content is lowered. The study has been made for different absorber gallium contents and the evolution is coherent with the presence of a cliff at the CIGSe/(PVD)In 2S 3 interface.

Influence of concentrations of copper, levelling agents and temperature on the diffusion coefficient of cupric ions in industrial electro-refining electrolytes

Few data are available for diffusion coefficients measured in industrial copper electrolytes. In the present work the influence of copper concentration (19.9–58.1 g dm−3), temperature (20–60°C) and concentrations levelling agents i.e. animal glue (0–5 mg dm−3) and thiourea (0–5 mg dm−3) on diffusion coefficients of copper was studied in industrial copper refinery electrolytes. Chronoamperometry at ultramicroelectrodes was used as an electrochemical technique. Apparent bulk diffusion coefficients were calculated on the basis of the theory of electrochemical nucleation on disc-shaped ultramicroelectrodes. Increasing copper concentration decreased the apparent bulk diffusion coefficient of copper and diffusion coefficients followed the Arrhenius temperature relationship. The experimental activation energy was 26.8 kJ mol−1. The influence of levelling agents on diffusion coefficients was not strong in the studied concentration range of animal glue and thiourea.

Influence of copper concentration on the ESR spectrum of Cu 2+ in CaO

Electron spin resonance (ESR) spectra of copper-doped calcium oxide have been studied at 77 K for Cu concentrations between 0.01 and 0.20 mol%. The results suggest that the range of the exchange interaction between Cu 2+ ions is 0.68 nm.

Hydrolysis of chlorpyrifos in natural waters of the Chesapeake Bay

Chlorpyrifos is the most widely used insecticide in the Chesapeake Bay region. Recent studies show that this organophospate chemical is consistently present in the air, rain and surface waters of the Chesapeake Bay region, suggesting a long environmental half-life. Hydrolytic degradation of chlorpyrifos is likely a dominant removal process, but existing hydrolysis data do not reflect conditions in the Chesapeake Bay. In this project, hydrolysis rates of chlorpyrifos were measured in sterilized, ambient water from the mouth of four Chesapeake Bay tributaries ranging in salinity from 0 to 17 ppt. The measured hydrolysis half-lives varied from 24 d in the Patuxent River to 126 d in the Susquehanna River. These results indicate that pH alone cannot be used as a single parameter to predict hydrolysis under field conditions. The influence of copper concentration, and other water constituents, need to be further evaluated as they may emerge as independent predictors to assess the fate of pesticides in natural systems.

Influence of copper concentration on the ESR spectrum of Cu 2+ in MgO

Electron spin resonance spectra of copper-doped magnesium oxide have been studied at room temperature for Cu concentrations between 0.10 and 0.50 mol%. The results suggest that the range of the exchange interaction between Cu 2+ ions is about 0.60 nm.

The influence of the mixing procedure and the copper proportion on the corrosion resistance of FeCu sintered products in SO 2 contaminated atmospheres

In this work, the corrosion resistance of FeCu sintered products, in simulated environments of atmospheres contaminated with SO 2, is studied through the use of the polarization resistance method using direct current. The importance of the mixing procedure of metallic powders during the preparation of the sintered products is stressed, with special emphasis being placed on the effectiveness of cementation of copper into the iron sponge in order to achieve products with a greater degree of corrosion resistance. The influence of copper concentration with time and sintering temperature is also analysed, establishing the corrosion resistance of final product.