Effect Of Copper Concentration Research Articles

Copper nanoparticles production by a novel non-dispersive membrane nanoprecipitation process

This study presents, for the first time, a novel route for producing elemental copper nanoparticles using a non-dispersive membrane nanoprecipitation process based on membrane contactors. Copper sulfate solutions ranging between 0.005 and 0.01 M Cu concentration were circulating through a hydrophobic polypropylene flat-sheet membrane, where hydrazine solutions with 1.84–3.64 M were fed by the other side of the membrane. The gradient of hydrazine concentration between both phases was the driving force that promoted the volatilization and transfer of hydrazine through the membrane pores, then reacting with cupric ions to precipitate elemental copper. The effects of copper concentration, hydrazine concentration, and temperature (20–40 °C) in the particle size distribution were assessed. Smaller nanoparticle sizes were obtained at the lowest copper concentration and the highest hydrazine concentration. Thus, the smallest copper nanoparticles were produced under the highest hydrazine/copper molar ratio, reaching values of around 200 nm. Besides, the precipitates showed a surface plasmon resonance, confirming the presence of elemental copper nanoparticles. Therefore, this study opens a new approach to producing metal nanoparticles with perspectives of application in industrial manufacturing, recovering valuable metals from mining effluent treatment, or even hydrometallurgical processes.

Optimising Wastewater Treatment: Acinetobacter sp. IrC1 as a potential multi-resistant bacterium for copper accumulation and dyes decolourisation.

Improper disposal of waste containing copper and dye is an environmental issue that must be resolved immediately due to its harmful, non-degradable and toxic properties. Bioremediation efficiency can improve by cultivating copper and dye multi-resistant bacteria to remove various pollutant types simultaneously. This study aims at establishing the multi-resistance of Acinetobacter sp. IrC1 to copper and dyes. The effects of copper concentration on growth were determined using a spectrophotometer, while accumulation was analysed using an atomic absorption spectrophotometer. Bacteria-mediated dye decolourisation dyes were observed based on clear zone formation around bacterial colonies, while decolourisation percentage was calculated using a spectrophotometer. Results demonstrate that Acinetobacter sp. IrC1 resisted up to 8 mM CuSO4 and accumulated up to 292.93 mg/g dry weight of copper cells. Acinetobacter sp. IrC1 isolates were also resistant to 500 ppm Methylene Blue, Malachite Green, Congo Red, Mordant Orange, Reactive Black, Direct Yellow, Reactive Orange, Remazol, Wantex Red and Wantex Yellow dye, successfully removing up to 68.35% and 79.50% Methylene Blue and Basic Fuchsine in a medium containing 3 mM CuSO4, respectively. Further investigations are required to analyse the genetic composition of multi-resistant bacteria to optimise the effectiveness of indigenous bacterial isolates as bioremediation agents.

Synthesis and characterization of chemical bath deposited copper doped lead sulfide thin films

ABSTRACT. The effects of copper concentration on the properties of copper lead sulfide thin films have been reported. Chemical bath deposition (CBD) method was used to deposit the ternary material on soda-lime substrates. Here, the films were grown using copper(II) chloride, lead nitrate, and thiourea as sources of copper (Cu), lead (Pb) and sulfur (S), respectively. The grown films were examined using X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, UV-spectrophotometer and four-point (4P) probes. XRD measurements revealed a polycrystalline material with strong adherent to the substrates. SEM readings indicated various grain-like crystalline morphologies with different sizes that change with copper concentrations. The EDX studies revealed that the deposited material consist of copper, lead and sulfur in various compositions. The transmittance was high in the near infrared regions of the electromagnetic radiation and, also decreases with copper concentrations. The band gap (Eg) varies from 2.05 to 2.50 eV with increase in copper concentrations. The study shows that CBD is an excellent method in depositing good quality films for device applications.
 
 KEY WORDS: Thin films, Substrates, Copper lead sulfide, Deposition, Optical properties
 Bull. Chem. Soc. Ethiop. 2023, 37(5), 1237-1251. 
 DOI: https://dx.doi.org/10.4314/bcse.v37i5.15

Electrocatalytic nickel-based coatings from an ammonia-sulfosalicylic bath for water splitting reactions

The synthesis and research of nickel and nickel-copper coatings on carbon felt from ammonium-sulfosalicylic electrolytes as electrocatalysts of water splitting reactions were carried out. The effect of copper concentration on electrochemical behavior was studied in the range of 5–15 g/L. The materials were investigated using SEM, XRD, EDX, and electrochemical methods. The average size of the crystallites is 15.1 and 16.4 nm for Ni-SS and NC-SS samples, respectively. The obtained materials have improved performance in the evolution reactions of hydrogen (HER) and oxygen (OER). Overpotentials equal to −120 mV for HER and 320 mV for OER on Ni-SS and −80 mV for HER and 300 mV for OER on NC–SS–10 were needed for a nominal current density of 10 mAcm−2. The stability test demonstrates that the overall water splitting occurs at 1.73 V to Ni-SS and 1.63 V to NC-SS. Impedance analysis indicates a decrease in complex resistance and resistance at the electrode-electrolyte interface for synthesized samples.

Improvement in Properties of Mild Steel by Electrodeposition of Ni-Zn-Cu Alloys at Different Cu Contents

In this study, the effect of copper concentration was investigated on phase structure, morphology, and mechanical properties of Ni-Zn-Cu alloys coating. Ternary Ni-Zn-Cu alloys were prepared and deposited on a mild steel substrate by electrochemical deposition method. Four different baths were prepared by varying Cu concentration. The deposition was carried out for 20 min with constant current density of 20 mAcm-2 with pH of 3 under constant magnetic field of 4.5 mT to make the coating smooth. Crystal structure, surface morphology, hardness and mechanical properties of investigated alloy coatings were characterized. The results showed that crystal structure of the all the deposited alloys is face centered cubic. The lattice parameter is decreasing and morphology of the alloys changes from large nodules to smaller nodules with the increase in Cu concentration. Mechanical properties of substrate are improved by deposition of Ni-Zn-Cu alloys and thus mild steel will become more applicable in tooling, construction and transportation industries.

Novel laboratory extraction method using magnetically micro bubble stream

Innovative, sensitive and accurate method for liquid-liquid extraction using bubble phenomenon. is presented in this work. A working system was designed, consisting of two basic parts: the pump air to generate the bubbles and the pump device, to pump or withdraw the organic layer from the liquid-liquid system key variables study was performed in the system containg Dithizone (0.001 M) in CHCl₃ solvent and aqueous copper (II) chloride (1000 ppm) solution to find out the extent of their impact on the extraction performance obtained in this way. The effect of copper concentration in the initial sample, shake time, size of bubbles flowrate were studied, fixing the optimal conditions: for a sample of (10 mL) aqueous solution of Cu (II) chloride, the optimum copper (II) concentration in the analyzed sample is (0.0001M) , the size of bubbles 2.6 L\min, the shaking time is (15 min), and the pump flowrate is ( 50sec/mL). In these optimum conditions, the extraction degree was (91.1 %). The results of the innovative bubbles extraction method were compared with previous studies, and found they were more efficient than the classical methods of extraction using funnel separation and multiple extraction.

Effects of copper concentration on the properties of Cu2CoSnS4 thin films co-electrodeposited on the FTO substrate

Effects of copper concentration on the properties of Cu2CoSnS4 thin films co-electrodeposited on the FTO substrate

Effect of Copper Concentration and Annealing Temperature on the Structure and Mechanical Properties of Ingots and Cold-Rolled Sheets of Al–2% Mn Alloy

Effect of Copper Concentration and Annealing Temperature on the Structure and Mechanical Properties of Ingots and Cold-Rolled Sheets of Al–2% Mn Alloy

Effect of copper concentration and annealing temperature on the structure and mechanical properties of Al–2wt.%Mn ingots and cold rolled sheets

This study focuses on the development of new Al–Cu–Mn alloys with enhanced strength and heat resistance achieved without hightemperature exposure. Seven alloys were considered including ones containing permanent Mn content of 2 % and variable Cu content of 0– 4 %. It was found that ~ 2 % Mn is completely dissolved in the solid solution of aluminum, while copper in the cast structure is distributed between the solid solution of aluminum and Al 2 Cu eutectic phase inclusions. It was experimentally established that when the copper content is 2 and 3 %, the solid solution of aluminum contains approximately the same amount of copper – up to 1.5 %. The deformation plasticity of experimental alloys in the cold rolling mode with the reduction rate of 80 and 95 % was investigated. It was shown that no preliminary treatment is required for alloys containing up to 3 % Cu as they feature high rolling workability. Then, the effect of heat treatment in the annealing temperature range of 200–600 °C on the structural and phase parameters of the alloys was studied. Alloy hardening in the process of multistage annealing by means of hardness measurement was analyzed. The data obtained allowed us to determine the influence of copper and analyze the thermal stability of model alloys. Tensile tests of cold rolled sheets with a thickness of 0.5 mm with a reduction rate of 95 % of alloys containing 2 and 3 % copper showed high performance. Particularly, the alloy containing 3 % Cu has strength compatible with that of the 1201 alloy in the T6 state.

Effect of copper concentration and sulfur vacancies on electronic properties of MoS2 monolayer: a computational study.

We investigated the geometrical and electronic properties of copper-doped MoS2 by first principles calculations. The doping is done by Cu substitution with Mo (1 to 4 atoms) accompanied by study of S vacancies. Our outcomes show that the concentration of doping and vacancy of S leads to determine and finely tune the band gap in the range of 0.16 to 1.95eV. This fine tuning of band gap results due to variation in concentration of impurity, changing dopant site, and production of S vacancies. The resulting arrangements show significant charge redistribution on replacement of local atoms with foreign atoms dictated by electronegativity determined from the Bader analysis. In addition, bonding mechanism occurring due to substitution of foreign elements is discussed. These results give pleasing data regarding fine desired value of the band gap of the MoS2 which helps its utilization in semiconductor and other opto-electronic devices in addition to understanding the electrical conductivity.

Effect of copper concentration on ethanol sensing performance of Cu-stilbite thick film sensor

The present study deals with natural stilbite zeolite commonly named as Ca-stilbite. Ion exchange process is carried out for partial exchange of calcium ions by copper ions. Ion exchanged stilbite is characterized by different spectroscopic techniques as XRD, FTIR and EDS techniques. Thick films are deposited on pre-cleaned glass substrates using screen printing technique. The sintered films are finally used for ethanol detecting. The Ca-stilbite zeolite structure is confirmed by the characterization techniques XRD and FTIR. Incorporation of copper ions in stilbite structure can be confirmed by EDS data. The Cu-stilbite films showed good ethanol detectors. The operating temperature, ethanol response, response/recovery nature are observed to be the functions of concentration of copper ions. Higher the copper concentration (0.2M) lower is the operating temperature (90°C) and higher is the ethanol sensitivity (233). It can be concluded that partial replacement of calcium by copper ions in stilbite leads to change in operating temperature and sensitivity.

Effect of Cu doping on the structural, optical and electrical properties of ZnO thin films grown by RF magnetron sputtering: application to solar photocatalysis

RF sputtered undoped and Cu doped ZnO (CZO) thin films were deposited on unheated glass substrates using a mixed Cu2O and ZnO powders target at different Cu concentrations of 0, 1, 2, 3 and 4 wt%. The effects of copper concentration on the structural, electrical, optical and photocatalytic properties of CZO films have been studied. From XRD and Raman spectroscopy studies, it was found that the deposited films were polycrystalline with a predominant hexagonal wurtzite structure along the c-axis perpendicular to the substrate surface. The presence of multiple interference fringes in the transmittance and reflectance spectra shows the good homogeneity of the films. All the films are highly transparent with transparency reaching 80% indicating the possibility to use these films as an optical window. The absorption tail gradually shifted towards a higher wavelength side, which resulted in the decrease of bandgap energy from 3.35 to 3.26 eV. All the sputtered films are highly conductive with a conductivity reaching 104 S.cm−1.The effect of Cu-doping on the photocatalytic activity of ZnO thin films for the degradation of methylene blue (MB) dye was studied under sunlight irradiation and the results showed that the Cudoping provokes appreciable degradation of MB and reached a maximum for the 1 wt% Cu doped ZnO film.

Effect of copper concentration on the structure of intermetallics and graphite additives of Al–Cu/C powder composites

The structure of hypo-eutectic and eutectic Al–Cu/C powder composites, as well as the powders with composition in the region of equilibrium Al4Cu9 phase, were studied using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and nuclear magnetic resonance (NMR) after high-energy ball milling of Al and Cu elemental powders with 5 wt.% of graphite additives and heat treatment at the temperature of 500 °C. Mechanical energy dose transferred into the powder composites during milling for 8 h was estimated to be 32 kJ/g and leads to the formation of the metastable disordered bcc-Al4Cu9 phase (A2 structural type) in a wide composition range. Effect of copper concentration on the peculiarities of its structure, chemical composition and the possibility of A2 → D83 first range ordering after heat treatment has been examined. Graphite additives structure evolution after milling and heat treatment of copper-rich Al–Cu/C powder composites was also specified.

Copper concentration effect on physical properties of ultrasonically sprayed Cu2ZnSnS4 absorber thin films for solar cell applications

Cu2ZnSnS4 (CZTS) thin films have been successfully deposited on glass substrate using ultrasonic spray pyrolysis (USP) technique with different copper concentrations ranging from 0.005 to 0.020 M. The effect of copper concentration on the structural, morphological and optoelectrical properties of deposited films has been investigated. Choice of USP method and copper concentration was found to have a crucial role in stoichiometry, band gap and conductivity of sprayed CZTS thin films. X-ray diffraction indicated that all deposited films have CZTS Kesterite structure with a preferential orientation along (112) plane confirmed by Raman scattering measurements. Copper sulfide (CuS) is present as a secondary phase in all films. The presence of this secondary phase causes films optical band broadening. Good film with nearly stoichiometric CZTS film and desirable band gap of 1.51 eV was obtained at copper concentration of 0.015 M. This result indicates that this film is suitable for being applied as an absorber layer in photovoltaic solar cells.

Effect of copper concentration on CTS thin films for solar cell absorber layer and photocatalysis applications

Abstract Earth abundant, nontoxic Cu2SnS3 (CTS) thin films are prepared using low-cost ultrasonic spray pyrolysis (USP) technique by varying different copper (Cu) precursor (copper chloride) concentration. Influence of Cu concentration on the electrical, optical and structural properties of CTS thin films are studied. XRD, TEM results confirm the formation of tetragonal structure of CTS films with orientation along (112) plane. Raman analysis reconfirms the tetragonal structure of CTS thin film and Cu2S secondary phase in films with higher Cu concentration samples. Stoichiometric film is found for 0.025M Cu concentration. XPS and PL studies are also performed. The absorption coefficient of CTS films is found to be ~105 cm−1 and optical bandgap is varying from 1.32 eV to 1.49 eV. P-type semiconductor nature of the film is found from electrical characteristics with carrier concentration of ~1021/cm3. The resistivity of the film decreases from 4.6 × 10−1 to 9.5 × 10−4 Ω-cm as Cu concentration increases. These properties are suitable for solar cell absorber layer. The optimized CTS thin film is used as a photocatalyst and photocatalysis activity of methylene blue (MB) dye is examined under visible light irradiation. A significant photodegradation (~90%) of MB achieved under 3 h visible light irradiation.

Effect of copper concentration on the structure and properties of Al–Cu–Fe and Al–Cu–Ni melts

We address a relationship between properties of liquid and solid states by comparing structural characteristics and viscosity in Al–Cu–Fe and Al–Cu–Ni melts. The former system forms an equilibrium quasicrystalline phase but the latter does not. We show that the concentration behavior of the viscosity, melting temperature and characteristics of the chemical short-range order correlate with each other. The main structural differences between the melts are related to the peculiarities of their electronic structure, which is the same for liquid and solid states near the melting temperature.

Pengaruh Konsentrasi Tembaga dan Rapat Arus terhadap Morfologi Endapan Elektrodeposisi Tembaga

Copper deposits have been obtained by the electrolysis method using copper sulfate and sulfuric acid. The effect of copper concentration and current density on the surface morphology of copper deposits and current efficiency have been studied. The variation of copper concentration is 0.04 M and 0.8 M and the variation of current density is 2-8 A/dm2. The copper deposits will be photographed macro, weighed and characterized by Scanning Electron Microscope (SEM) to determine the surface morphology of deposits and Energy-Dispersive X-ray spectroscopy (EDX) to determine the chemical composition of deposits. The surface morphology of copper deposits in the form of compact and without nodules was reached at copper concentration is 0.8 M and the current density is 2 A/dm2 with the average of current efficiency is 96%.

The role of copper during the growth of stoichiometric Cu2ZnSnS4 by successive ionic layer adsorption and reaction method

The synthesis and characterization of Cu2ZnSnS4 (CZTS) thin films prepared on glass/CdS substrates by the successive ionic layer adsorption and reaction (SILAR) method are presented. The effect of copper concentration and atmosphere annealing on the properties of CZTS thin films were studied by means X-ray diffraction (XRD), Raman spectroscopy, Scanning Electron Microscopy (SEM), X-ray photoelectron spectroscopy (XPS), optical spectroscopy and current-voltage curves. The XPS depth profiling data revealed that a minima copper concentration in cationic solution is required to start the adsorption of zinc and tin ions at the CdS surface. The use of 0.001–0.002 M copper concentration allows the adsorption of zinc and tin ions in a suitable quantity inducing the formation of stoichiometric and polycrystalline CZTS thin films. Furthermore, it was found that above of this copper concentration, the segregation of Cu2S phase occurs, even when it is ten times smaller than Zn and Sn concentrations. Otherwise, the sulfurization process doesn't imply a significant change on the structural and chemical properties, as if it does in the optical and electrical properties. This suggests that the excess of Na2S used in the anionic solution is enough to compensate the loss of sulfur during the thermal annealing. The optical band gap energy and the electrical conductivity of these films were evaluated in the range of 1.41–1.53 eV and 10−1 Ω cm−1, respectively. All results suggested that this material is suitable for being applied as an absorber layer in photovoltaic solar cells.

Effect of copper concentration on physical properties of CZTS thin films deposited by dip-coating technique

Cu2ZnSnS4 (CZTS) thin films have been prepared via sol–gel method and deposited on ordinary glass substrates by dip-coating technique. The chemical composition of Cu/(Zn + Sn) ratio was varied between 0.85, 0.95 and 1.05 to study its effect on structural, optical, morphological, compositional and electrical properties of deposited films. The films were investigated using different techniques such as X-ray diffractometer (XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), UV–vis spectrophotometer and four-point probe method. The X-ray diffraction showed the single kesterite phase with the preferential orientation along (112) plane. The crystallites size was found to be between 6.95 and 9.30 nm. Raman scattering measurements for CZTS films deposited at Cu/(Zn + Sn) equal to 0.85 and 1.05 were confirmed the presence of pure CZTS phase by the characteristic peak at 332 cm−1. The morphological properties show a dense surface morphology and the elemental composition indicates CZTS films with a near-stoichoimetric composition. The optical properties were calculated using transmittance and absorbance data in the wavelength range between 450 and 850 nm. The obtained band gap energy values were found to be between 1.41 and 1.47 eV. The electrical sheet resistance showed values between 0.68 and 1.07 × 103 Ω square−1. A best sheet resistance and favorable optical band gap make our dip-coated CZTS thin films suitable to be used as an absorber layer for photovoltaic applications.

The Toxicity of Copper to Crocosphaera watsonii and Other Marine Phytoplankton: A Systematic Review

The cupric ion (Cu2+) plays a dual role as both nutrient and toxicant to terrestrial and marine phytoplankton, functioning in multiple photochemical processes, as well as reactive oxygen species (ROS) production. This duality has been investigated through a variety of methods to determine the consequences of natural and anthropogenic copper introduction to algal ecosystem composition. Studies conducted over the past few decades have described the growth responses of many unique organisms to copper availability. Such observations are critical for describing the global distributions of major phytoplankton species in terms of global trace metal abundance; however, highly variable experimental practices impede direct inter-study comparison. The aim of this systematic review is to summarize the available data regarding the effects of copper concentration on diverse marine phytoplankton growth rates. Through extensive literary comparison, 143 studies were systematically reviewed, and data on copper concentrations and growth rates reported were extracted. From the data available, we conclude that trends in phytoplankton sensitivity to copper are mainly driven by a single study. We discuss the obstacles to inter-study comparison and detail both the concurring and conflicting results to date, with an emphasis on taxonomic trends and methodologies employed. Finally, we present the first copper sensitivity measurements for marine unicellular diazotrophs using three representative strains of the unicellular nitrogen-fixing cyanobacterium, Crocosphaera watsonii.