Aqueous Solution Of Copper Chloride Research Articles

Sorption of Metal Ions from Aqueous Solutions by Crown Ethers

Abstract—The sorption of copper and lead ions by polymeric sorbents based on crosslinked polyacrylamide containing chemically bound or immobilized 15-crown-5 and 18-crown-6 was studied, as was the effect of various parameters on the efficiency of metal sorption from aqueous solutions. It is shown that the sorption capacity of these sorbents increases dramatically with an increase in the content of crown ethers in them from 3 to 6 wt %. When aging sorbents containing 6 wt % 15-crown-5 or 18-crown-6, in an aqueous solution of copper chloride or lead acetate, respectively, the salt concentration in the solution decreases by 3–4 orders of magnitude. When aging sorbents based on 18-crown-6 in a solution containing equivalent amounts of lead acetate or copper sulfate, the amount of absorbed copper did not exceed 5% of the amount of extracted lead, which indicates the high selectivity of such sorbents.

Ecological Roles of Tryptanthrin, Indirubin and N-Formylanthranilic Acid in Isatis indigotica: Phytoalexins or Phytoanticipins?

Leaves of the plant species Isatis indigotica Fortune ex Lindl. (Chinese woad) produce the metabolites tryptanthrin, indirubin and N-formylanthranilic acid upon spraying with an aqueous solution of copper chloride but not after spraying with water. The antifungal activities of these metabolites against the phytopathogens Alternaria brassicicola, Leptosphaeria maculans and Sclerotinia sclerotiorum established that tryptanthrin is a much stronger growth inhibitor of L. maculans than the phytoalexin camalexin. The biosynthetic precursors of tryptanthrin and N-formylanthranilic acid are proposed based on the deuterium incorporations of isotopically labeled compounds. The overall results suggest that tryptanthrin is a phytoalexin and indirubin and N-formylanthranilic acid are phytoanticipins in the plant species I. indigotica and that chemical diversity and biodiversity are intimately connected.

Ultrasonic Spray Pyrolysis Deposited Copper Sulphide Thin Films for Solar Cell Applications.

Polycrystalline copper sulphide (CuxS) thin films were grown by ultrasonic spray pyrolysis method using aqueous solutions of copper chloride and thiourea without any complexing agent at various substrate temperatures of 240, 280, and 320°C. The films were characterized for their structural, optical, and electrical properties by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), atomic force microscopy (AFM), contact angle (CA), optical absorption, and current-voltage (I-V) measurements. The XRD analysis showed that the films had single or mixed phase polycrystalline nature with a hexagonal covellite and cubic digenite structure. The crystalline phase of the films changed depending on the substrate temperature. The optical band gaps (Eg) of thin films were 2.07 eV (CuS), 2.50 eV (Cu1.765S), and 2.28 eV (Cu1.765S–Cu2S). AFM results indicated that the films had spherical nanosized particles well adhered to the substrate. Contact angle measurements showed that the thin films had hydrophobic nature. Hall effect measurements of all the deposited CuxS thin films demonstrated them to be of p-type conductivity, and the current-voltage (I-V) dark curves exhibited linear variation.

Growth of spray pyrolysis deposited copper oxide thin film

Copper oxide thin film is deposited on the glass slide using aqueous solution of copper chloride and hydrogen peroxide by using spray pyrolysis deposition technique. The deposited CuO thin film is adherence and homogeneity with high transparency in visible region. Investigation of CuO thin film for physical properties is done. By using UV –Visible Spectrophotometer optical properties like absorption, transmission, energy band gap, Absorption coefficient and extinction coefficient in the visible region (380 – 1000 nm) are studied. The X-ray diffraction of CuO thin film is polycrystalline in nature with monoclinic crystal structure. The resistivity of Cuo thin film is studied using four probe methods.

Intermediates in the cation reactions in solution probed by an in situ surface enhanced Raman scattering method.

For chemical reactions in liquid state, such as catalysis, understanding of dynamical changes is conducive to practical applications. Solvation of copper salts in aqueous solution has implications for life, the environment, and industry. In an ongoing research, the question arises that why the color of aqueous CuCl2 solution changes with solution concentration? In this work, we have developed a convenient and efficient in situ surface enhanced Raman scattering technique to probe the presence of many intermediates, some of them are responsible for color change, in crystallization of aqueous copper chloride solution. The versatility of the novel technique was confirmed in the identification of five intermediates states in the transition from CdS to MoS2 nanowires in solution. The facile in situ method is expected to be widely applicable in probing intermediate states in a variety of chemical reactions in solution.

Thermal behaviour of precursors for CuInS2 thin films deposited by spray pyrolysis

The thermal decomposition of precursors for copper indium disulphide (CuInS2) thin films obtained by drying aqueous solutions of copper chloride (CuCl2), indium chloride (InCl3) and thiourea (SC(NH2)2) at the Cu:In:S molar ratios of 1:1:3 (1) and 1:1:6 (2) was monitored by simultaneous thermogravimetry /differential thermal analysis/ evolved gas analysis-mass spectrometry (TG/DTA/EGA-MS) measurements in a dynamic 80 %Ar + 20 %O2 atmosphere. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were used to characterise the dried precursors and products of the thermal decomposition. The precursors 1 and 2 are mixtures of copper and indium chloride thiourea complex compounds, whilst 1 can also contain unreacted InCl3. The thermal degradation of 1 and 2 in the temperature range of 30–800 °C consists of six steps with a total mass loss of 71.5 and 89.8 %, respectively. According to XRD, CuInS2 is formed below 300 °C. Decomposition of 1 and 2 is completed at 620 and 600 °C, respectively. The final decomposition product of 1 at 800 °C consists of a mixture of In2O3 and CuO phases, whilst 2 consists of In2O3, CuO and Cu2In2O5 phases. EGA by MS revealed the release of CS2, NH3, H2NCN and HNCS, which upon their oxidation also yield COS, SO2, HCN and CO2.

Carbonate‐Assisted Hydrothermal Synthesis of Nanoporous CuO Microstructures and Their Application in Catalysis

AbstractWe have demonstrated a facile carbonate‐assisted hydrothermal route for synthesis of well‐defined nanoporous copper oxide microstructures with high surface area. The nanoporous CuO microstructures were synthesised by adding sodium hydrogen carbonate (NaHCO3) to an aqueous solution of copper chloride (CuCl2) in the presence of poly(vinylpyrrolidone) (PVP) at 300 °C. The introduction of NaHCO3 is critical for the successful synthesis of porous nanoarchitectures owing to the formation of carbon dioxide (CO2) gas during the synthesis process. The structure and morphology of CuO are very sensitive to the concentration of NaHCO3 and PVP, as well as to the molecular weight of PVP. The nanoporous CuO product shows higher catalytic activity than other types of CuO materials because of its porous structure. It is believed that this method will provide a simple and versatile approach to large‐scale production of CuO with high surface area by means of a facile hydrothermal route.

Laser-induced modification of composite Cu-C nanosized particles synthesized using a pulsed electrical discharge in a liquid

Composite copper-containing carbon nanosized structures were synthesized in the plasma of a pulsed electrical discharge, initiated between two graphite electrodes in an aqueous copper chloride solution. We studied the effect of laser radiation on the morphology of the nanoparticles formed, whose properties we studied by optical absorption spectroscopy and transmission electron microscopy. We discuss the mechanisms for nanoparticle formation in a discharge submerged in a liquid, and the possibilities for laser-induced modification of the nanoparticles. We estimated the temperature of the nanoparticles when exposed to laser radiation pulses.

CuO-modified tin titanate thick film resistors as H 2-gas sensors

Thick films of pure and CuO-modified tin titanate—Sn 0.8Ti 0.2O 2 (TT) were prepared by screen printing technique. Unmodified TT showed poor sensitivity while CuO-modified TT showed high sensitivity to H 2 gas. The CuO-modified TT films were obtained by dipping them into an aqueous solution of copper chloride for different intervals of time and fired at 500 °C for 30 min. The copper chloride transforms into copper oxide upon firing. A relatively large amount of oxygen would be adsorbed on the CuO-modified TT and resulted in the buildup of potential barriers between the grains. Upon exposure to 1000 ppm H 2 gas, the barrier height would decrease markedly due to oxidation leading to a drastic decrease in resistance and giving high sensitivity to H 2 gas. High sensitivity was found to H 2 gas at 400 °C and no cross response was observed to LPG, NH 3, C 2H 5OH, CO 2 and Cl 2 gases. The instant response (∼15 s) and fast recovery (∼45 s) are the main features of this sensor. The effects of microstructure and concentration of the CuO additive on the gas response, selectivity, response time and recovery time were studied and discussed.

Studies on gas sensing performance of (Ba 0.8Sr 0.2)(Sn 0.8Ti 0.2)O 3 thick film resistors

Thick films of (Ba 0.8Sr 0.2)(Sn 0.8Ti 0.2)TiO 3 (BSST) were prepared by screen-printing techniques. The surfaces of the films were modified by dipping them into an aqueous solution of copper chloride for different intervals of time, followed by firing at 550 °C for 30 min. The gas sensing performance of the unmodified and CuO-modified films was tested for various gases. The unmodified films showed response to ethanol and the CuO-modified films to SO 2 gas. The surface modification, using dipping process, altered the adsorbate–adsorbent interactions, which gave the unusual sensitivity and selectivity effect. The gas response, selectivity, thermal stability, response and recovery time of the sensor were measured and presented. The role played by surface copper species in the gas sensing performance is discussed.

Heterocontact type CuO-modified SnO 2 sensor for the detection of a ppm level H 2S gas at room temperature

Thick films of SnO 2 were prepared by screen printing technique. The films were modified with Cu 2+ by dipping them into an aqueous solution of copper chloride for different intervals of time and fired at 550 °C for 24 h. The copper chloride would be transformed upon firing into copper oxide. The p-type CuO grains around n-type SnO 2 grains would form n-SnO 2/p-CuO heterojunctions. Upon exposure to H 2S gas, the barrier height of n-SnO 2/p-CuO heterojunctions decreases markedly due to the chemical transformation of p-CuO into well conducting Cu 2S, leading to a drastic change in resistance. These sensors were observed to be operated at room temperature. An exceptional sensitivity was found to low concentrations (below threshold limit value = 10 ppm) of H 2S gas at room temperature, and no cross sensitivity was observed even to high concentrations of other hazardous and polluting gases. The efforts have, therefore, been made to develop the heterocontact type gas sensor based on tin oxide surface-modified with cupric oxide. The effects of microstructure and surfactant concentration on the sensitivity, selectivity, response and recovery of the sensor in the presence of H 2S gas were studied and discussed.

Structural evolution and optical characterization of indium doped cadmium sulfide thin films obtained by spray pyrolysis for different substrate temperatures

Indium doped cadmium sulfide thin films were prepared by spray pyrolysis on glass substrates at different temperatures ranging from 300°C to 450°C in 25°C steps, using aqueous solution of copper chloride and thiourea salts. We used In(COOH)3 as the dopant. Structural characterization was carried out by X-ray diffractometry and scanning electron microscopy and high resolution electron microscopy were used together with atomic force microscopy (AFM) to follow the evolution of structural and morphological parameters of the films with substrate temperature (Ts). At least two preferential growth, (1 1 2) for samples with Ts between 325°C and 400°C and (0 0 2) for Ts between 400°C and 450°C, respectively were detected. For the films obtained at higher substrate temperatures, HREM micrographs revealed the presence of a large number of structural defects together with nanostructured configurations. AFM revealed surface modifications of CdS:In grains at higher substrate temperature. The substrate temperature is directly related with the shift detected in the band gap values derived from optical of parameters.

Preparation and characterization of copper indium diselenide films by electroless deposition

The preparation of copper indium diselenide (CIS) films by electroless deposition technique is reported. The films have been deposited on molybdenum substrates. The deposition bath consisted of aqueous solutions of copper chloride, indium chloride, selenous acid and lithium chloride. The pH of the bath was adjusted to 2.2 by adding dilute HCl. The Mo substrate was short-circuited with the aluminum counter electrode for the electroless deposition. The films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDXA), inductively coupled plasma spectroscopy (ICP), Auger electron spectroscopy (AES) and optical spectroscopy. The results indicate that reasonable quality CIS films can be grown by simple electroless deposition process followed by recrystallization in selenium atmosphere.

Structural and optical properties of sprayed CuInS 2 films

Polycrystalline CuInS 2 thin films have been prepared by spray pyrolysis of aqueous solution of copper chloride, indium chloride and thiourea onto heated glass substrates. It is shown that the parameters critical to structural and optical properties of sprayed CuInS 2 films are growth temperature and ion ratio of Cu/In in spraying solution. Excess of copper in starting solution promotes the recrystallization and growth of crystallites in the film. The X-ray diffraction patterns confirm that the use of copper-rich solutions reduces the temperature required for single-phase composition of CuInS 2 films from 380°C ( Cu/In=1 ) to 290°C ( Cu/In=1.25 ). The formation of CuInS 2 in spray process and chemical nature of additional phases in the films are discussed. Growth temperatures in the range of 320–380°C at Cu/In>1 are determined as optimal for depositing orientated in the (112) direction CuInS 2 thin films with chalcopyrite structure. Sprayed chalcopyrite CuInS 2 films have absorption coefficient ∼10 5 cm −1in visible and red region of spectra and optical band gap 1.45 eV.

Combined effects of copper, desiccation, and frost on the viability of earthworm cocoons

AbstractThe effects of heavy metal pollution on earthworms have been extensively studied, but no studies have examined how earthworms react if they are simultaneously exposed to metal pollution and climatic stress. This question has been addressed in a laboratory study where cocoons of Aporrectodea caliginosa and Dendrobaena octaedra were initially exposed to copper in aqueous solutions of copper chloride and thereafter exposed to realistic degrees of either desiccation or frost. Earthworm embryos absorbed copper in amounts (up to approx. 200 mg/kg dry tissue weight) comparable to concentrations found in various tissues of earthworms from metal‐polluted soils. Desiccation and copper exposure in combination had synergistic effects on survival rates for both species. For example, at full saturation, the NOEC (the highest tested concentration with no statistically significant effect) for copper of A. caliginosa was 12 mg/L, whereas at 97% relative humidity it was only 6 mg/L. Frost and copper exposure in combination also showed synergistic effects in some experiments. No cocoons of A. caliginosa exposed to 20 mg copper/L were viable after exposure to −3°C but at 0°C viability was as high as 95%. The same tendency was seen in D. octaedra but not as clearly as in A. caliginosa. A change of the environmental conditions (moisture, temperature) to increasing severity caused a shift in the statistically derived NOEC toward lower critical values of copper. The involvement of combination effects in ecotoxicological tests could therefore improve risk assessment of soil‐polluting compounds.

Monte Carlo simulations of copper chloride solutions at various concentrations including full 3-body correction terms

Aqueous copper chloride solutions at concentrations of 1, 3 and 5 mol kg −1 have been investigated by means of Metropolis Monte Carlo simulations. The structural results are compared with experimental data on species formation and structure of these solutions. As pair potentials are insufficient to describe solvation phenomena correctly, three-body terms were incorporated, based on ab initio calculations for the interactions Cu 2+H 2OH 2O and Cu 2+Cl −H 2O. The simulations were performed with three-body correction for the Cu 2+H 2OH 2O alone and with three-body corrections for both Cu 2+H 2OH 2O and Cu 2+Cl −H 2O. The structure of the solvated copper(II) ion is discussed in terms of radial density functions and coordination number distributions. The correction of the Cu 2+Cl −H 2O interactions proved absolutely necessary to achieve reliable structural results, whereas three-body effects corresponding to Cl −Cu 2+Cl − interactions could be neglected, since in most species two chloride ions are located in trans-positions.

Synthesis of Copper Nanoparticles in Nonionic Water-in-Oil Microemulsions

Synthesis of well-dispersed copper nanoparticles was achieved by reduction of aqueous copper chloride solution using NaBH4in the nonionic water-in-oil (w/o) microemulsions formed by Triton X-100,n-hexanol, cyclohexane, and water. It has been shown that instead of copper oxide produced in aqueous solution, metallic copper particles are formed in w/o microemulsions because of the high local copper concentration in water pools of the microemulsions, indicating the advantage offered by w/o microemulsions over aqueous phases. The absorption spectrum of the colloidal copper particles obtained in microemulsions does not exhibit the plasmon peak characteristic of the Cu surface. It is conceivable that the lack of the plasmon absorption band is attributed to the formation of a CuCl monolayer on the copper particles.

Structure of aqueous copper chloride solutions: results from Monte Carlo simulations at various concentrations

Monte Carlo simulation results are reported for aqueous copper chloride solutions in the concentration range (1–5 mol kg–1) and compared with experimental data on the species formation and structure of these solutions. The structural data from the simulations suggest which of the quite contradictory interpretations of experimental results is to be preferred. Special emphasis was given to the formation of CuCl(2–n)–n complexes, and the formation constants evaluated from the simulation are in good agreement with experimental data, underlining the reliability of the structural data. Whereas in 1 mol kg–1 solution direct copper–chloride binding does not occur, CuCl+ is the dominant species in 3 mol kg–1 solution. In 5 mol kg–1 solution, complexes of copper with 1–4 chloride ions are observed. Structural details of the complexes are visualized by ligand distribution plots, showing a breakdown of the order of the hydration structure at high salt concentrations. Indications were obtained that CuCl+ is the main active species inducing peptide condensation of amino acids in aqueous solution.

The fate of gold in cupric chloride hydrometallurgy

Because of the importance of gold in copper processing, controlled experiments were performed with gold metal and aqueous copper chloride solutions to characterize the behavior of gold under leach conditions and understand its disposition during the processing of ore concentrate and gold-containing alloys. These experiments were done under an inert atmosphere and also with exposure to air. A model of the aqueous solution resulting from leaching was also developed for correlating experimental results and predicting gold behavior. It was based on simple leach reactions for both gold and copper and the complex ions which are formed in the presence of strong saline solutions. The experimental results are compared with predictions and it is shown that the model is viable for predicting the effect of varying sodium chloride, cupric chloride and cuprous ion concentrations in leaching solutions. The effects of raising temperature and exposure to oxygen were also studied and both are shown to increase gold solubility in leach solutions. An increase in cuprous ion concentration in leach solution is shown to limit gold solubility as well as cause precipitation.

Cu2+coordination in aqueous solution

A neutron diffraction study has been made to determine the environment of the Cu2+ ion in a 4.32 molal aqueous solution of copper chloride. The results show that the Cu2+ ion coordination exhibits a clear 2-4 character. The two nearest neighbours are identified with (heavy) water molecules with atom positions of rCuO=2.05+or-0.02 AA and rCuD=2.56+or-0.10 AA. This coordination differs from that for divalent ions of comparable size and represents clear structural evidence that chemical effects are dominant in the immediate neighbourhood of Cu(II) ions.