Potential For Cu Research Articles

Atomic cluster expansion interatomic potential for defects and thermodynamics of Cu–W system

The unique properties exhibited in immiscible metals, such as excellent strength, hardness, and radiation-damage tolerance, have stimulated the interest of many researchers. As a typical immiscible metal system, the Cu–W nano-multilayers combine the plasticity of copper and the strength of tungsten, making it a suitable candidate for applications in aerospace, nuclear fusion engineering, and electronic packaging, etc. To understand the atomistic origin of the defects (e.g., vacancies, free surfaces, grain boundaries, and stacking faults and thermodynamical properties), we developed an accurate machine learning interatomic potential for Cu–W based on the atomic cluster expansion (ACE) method. The Cu–W ACE potential can faithfully reproduce the fundamental properties of Cu and W predicted by density functional theory (DFT) calculations. Moreover, the thermodynamical properties, such as the melting point, coefficient of thermal expansion, diffusion coefficient, and equation of the state curve of the Cu–W solid solution, are calculated and compared against DFT and experiments. Monte Carlo molecular dynamics simulations performed with the Cu–W ACE potential predict the experimentally observed phase separation and uphill diffusion phenomena. Our findings not only provide an accurate ACE potential for describing the Cu–W immiscible system but also shed light on understanding the atomistic mechanism during the Cu–W nano-multilayers formation process.

Biochar modified by ammonium pyrrolidine dithiocarbamate for high selective adsorption of copper in wastewater

Biochar application in wastewater purification is extremely appealing. Although heteropolysaccharides like Gum Seyal biochar (BC GS500) display great surface area and porosity, the adsorption capacity for Cu (II) was relatively low due to the week-binding surface functional groups. In this work, an innovative modification with the chelating agent ammonium pyrrolidine dithiocarbamate (APDC) capable of selectively and effectively adsorbing Cu (II) was conducted. Gum Seyal biochar was grafted with pyrrolidine dithiocarbamate (C5H8NS2–), amine (–NH2), and imine (–NH) groups using APDC based on the “hard and soft acids and bases theory” (HSAB). Batch studies, along with characterization (FITR, XPS, and SEM-EDS), molecular electrostatic potential (MEP) mapping, and density functional theory (DFT) calculations, were implemented to investigate the adsorption performance and mechanism responsible for selectively adsorptive Cu (II) removal. It was found that Cu (II) adsorption by modified biochar occurred endothermically and spontaneously. The adsorption data at pH 5 matched the pseudo-second-order kinetic model and the Langmuir isotherm (211.24 mg/g). DFT calculations show that modified biochar selectively binds Cu (II) superior to common ions such as Mg (II) and Ca (II) through a unique chelating mechanism. Their performance in real electroplating wastewater was investigated, and the production cost was estimated. It was concluded that the modified biochar (BC APDC) could have high applicable potential for Cu (II)-laden wastewater purification.

Cu(II) Biosorption and Synthesis of CuO Nanoparticles by Staphylococcus epidermidis CECT 4183: Evaluation of the Biocidal Effect

Copper contamination of natural waters is a global problem that affects ecosystems and public health, yet this metal is an essential micronutrient and has important applications. The efficacy of Staphylococcus epidermidis CECT 4183 as a Cu(II) biosorbent in synthetic solutions and its potential ability to synthesize CuO nanoparticles (CuO-NPs) from its cellular extract was investigated. In addition, the biocidal potential of the nanoparticles was evaluated against five microorganisms. Using response surface methodology, the optimal operating conditions were determined to be biomass dose, 0.2 g/L, and pH 5.5. Equilibrium tests were performed, and biosorption isotherms were obtained for four models with a maximum biosorption capacity of 48.14 mg/g for the Langmuir model. Different spectroscopic and microscopic techniques were used to determine the mechanisms involved in the biosorption process, which was dominated by surface physicochemical interactions with strong involvement of methyl, methylene, carbonyl, amino, and phosphate groups. The techniques also allowed for characterizing the obtained nanoparticles, which had a quasi-spherical morphology and an average size of 14 nm. Finally, biocidal tests showed that the CuO-NPs had a good inhibitory capacity for the microorganisms tested, with minimum inhibitory concentrations (MIC) between 62.5 and 500 µg/mL for bacteria and between 1000 and 2000 µg/mL for yeasts. S. epidermidis CECT 4183 showed good potential for Cu(II) bioremediation and for the synthesis of CuO-NPs with biocidal capacity. S. epidermidis CECT 4183 showed good potential for use in Cu(II) biosorption, and its cell extract presented a high capacity for the green synthesis of CuO-NPs, which at the same time turned out to be good biocidal agents.

Adsorption behavior of heavy metals onto microplastics derived from conventional and biodegradable commercial plastic products

This study extensively explored the adsorption behavior of heavy metals (Pb+2, Ni+2, Cu+2, Zn+2, and Cd+2) onto microplastics (MPs). The particle sizes of MPs ranged from 0.149 to 0.25 mm. The microplastics were generated from commercial products manufactured from both conventional (polyethylene (PE) bottle, polystyrene (PS) spoon, and polyethylene terephthalate (PET) egg carton) and biodegradable (polylactic acid (PLA) spoon, and polylactic acid (PLA) egg carton) plastics. The study also considered the influence of solution pH on the adsorption capacity of heavy metals. Regarding the adsorption potential for Cu+2, the ranking was as follows: PLA-egg (1408 μg·g−1) > PLA-spoon (735 μg·g−1) > PE-bottle (315 μg·g−1) > PET-egg (283 μg·g−1) > PS-spoon (237 μg·g−1). PLA MPs showed the highest adsorption capacity due to the lower thermal stability and higher presence of surface oxygen functional groups. Moreover, the adsorption capacities of the five metals onto PLA-spoon and PLA-egg decreased in the following order: Pb (1785 μg·g−1) > Zn (1267 μg·g−1) > Cd (748 μg·g−1) > Cu (735 μg·g−1) > Ni (722 μg·g−1), and Pb (1520 μg·g−1) > Ni (1412 μg·g−1) > Cu (1408 μg·g−1) > Zn (1118 μg·g−1) > Cd (423 μg·g−1), respectively. The SEM-EDS, FTIR and XPS results demonstrated that surface oxygen-containing functional groups play an important role during the adsorption process. This study extended its analysis to quantify the metal content of the post-adsorption MPs, revealing uneven adsorption of heavy metals onto the MPs. This implies that the diversity of commercial plastic products may result in significant variations in their ability to adsorb heavy metals, underscoring the importance of effectively managing discarded commercial plastic products.

Differences in the spectral characteristics of dissolved organic matter binding to Cu(II) in wetland soils with moisture gradients

The environmental behavior of heavy metals in soil is significantly regulated by their binding with dissolved organic matter (DOM), which is affected by soil moisture contents. However, the mechanism of this interaction in soils with varying moisture is still not well understood. Using a combination of ultrafiltration, Cu(II) titration, and multispectral (ultraviolet-visible absorption, 3D fluorescence, Fourier transform infrared) analysis techniques, we studied the differences in the spectral characteristics and Cu(II) binding properties of soil dissolved organic matter (DOM) and its different molecular weight (MW) fractions with moisture gradients. We found that the abundance and spectral characters of soil DOM changed with increasing soil moisture, i.e., the increase in abundance while the decrease in aromaticity and humification index. The components of DOM, shown by Fluorescence region-integration (FRI) analysis, also changed, with an increase in the proportion of protein-like substances and a decrease of humic-like and fulvic-like substances. The overall Cu(II) binding potential of soil DOM diminished with increasing soil moisture, as indicated by the fluorescence parallel factor (PARAFAC) analysis. This is aligns with the changes in DOM composition, as the humic-like and fulvic-like fractions exhibited higher Cu(II) binding potential compared to the protein-like fractions. The low MW fraction of the MW-fractionated samples showed a stronger binding potential for Cu(II) compared to the high MW fraction. Finally, the active binding site of Cu(II) in DOM, as revealed by UV-difference spectroscopy and 2D-FTIR-COS analysis, decreased with increasing soil moisture, with the order of preferentially functional groups shifting from OH, NH, and CO to CN and CO. This study emphasizes the impact of moisture variations on the characteristics of DOM and its interaction with Cu(II), providing insight into the environmental fate of heavy metal contaminants in soil in areas with alternating land and water conditions.

A Comparative study of the mineral composition of Macrotermes and Cubitermes termite mounds in Lualaba, D.R. Congo: Contribution to strategic prospecting for Cu and Co deposits

This work focuses on the comparative analysis of the influence of two termites of the Macrotermes (fungus-growing) and Cubitermes (soil-feeding termites) genera on the dynamics of soil lithogeochemical facies. The aim was to establish a general systematic recognition of the lithology of a large area, including its potential for Cu and Co mineralization. Eighty-eight samples of the mound material were collected from termite mounds of these two species along a 50 km transect in Lualaba Province, Democratic Republic of Congo (DRC) in order to carry out major and trace element analyses. Interpretation of the data was carried out through exploratory analysis, using the Ascending Hierarchical Classification (AHC) method and Principal Component Analysis (PCA), followed by statistical modeling using linear regression. After clustering the termite mounds into classes by AHC, an initial PCA was used to map the lithology of these classes using major elements. The results highlight the dependance of the lithological composition of the mounds on the behavior specific to each of the two termite species. Linear regression modeling allowed a delineation of the area of supply of building materials for each species, indicating the possible incorporation of Cu and Co mineralizations likely to be present in the environment of the termite mounds. The use of termite mounds as a tool in mining exploration is discussed.

The impact of misorientation on the grain boundary energy in bi-crystal copper: an atomistic simulation study.

Atomistic simulations were performed to investigate the relationships among the misorientation, dislocation density, and grain boundary energy of twist and tilt bi-crystal grain boundaries. In this work, the grain boundary energies were calculated based on the embedded-atom method interatomic potential for Cu. The results show that the dislocation density of the grain boundary changes with the rotation angle, thereby affecting the grain boundary energy. Furthermore, the grain boundary energy of a grain boundary with no dislocations is greater than that of a grain boundary with dislocations, which results from the distribution of the atomic potential energy on the grain boundaries. Additionally, the grain boundary energy increases with the dislocation density of the grain boundary in the case of dislocations on the grain boundary. On this basis, a new relationship is proposed for the misorientation angle and grain boundary energy. We assume that when the driving force of dislocation nucleation breaks through the grain boundary energy barrier, the grain boundary energy declines.

Trace Elements in Crustaceans, Mollusks and Fish in the Kenyan Part of Lake Victoria: Bioaccumulation, Bioindication and Health Risk Analysis

This is the first comprehensive report on the accumulation of Cr, Ni, As, and Ag in the fish species Nile tilapia Oreochromis niloticus and Nile perch Lates niloticus from Lake Victoria, complemented with recent data on Cu, Zn, Cd, and Pb. This also is the first report on Cr, Ni, As, and Ag levels in invertebrates: the shrimp Caridina nilotica, gastropod Pila ovata, and bivalve Mutela bourguignati. The study was conducted at five sites in the Kenyan part of Lake Victoria: four sites in Winam Gulf influenced by various anthropogenic pressures, including a site near Kisumu City, and one in the main lake, with lesser direct anthropogenic influence. Apart from Cu and Ag, which were highest in O. niloticus liver, the invertebrates had higher levels of trace elements than fish. Contamination of the gulf with trace elements was best mirrored by the invertebrates, whose mobility is limited; they accumulated Cr, Cd, Ag, and Pb corresponding to the levels in the surface sediment. The accumulation of trace elements in fish species and their bioindicative potential corresponded to their habitats and feeding behaviour. The tissue contents of most trace elements were higher in the inshore-dwelling, omnivorous O. niloticus compared to the pelagic, piscivorous L. niloticus. Cu (465 ± 689 mg/kg dw) and Ag (3.45 ± 1.49 mg/kg dw) in the liver of O. niloticus were up to 10 and 119 times higher than in L. niloticus, respectively. Oreochromis niloticus therefore has bioindicative potential for Cu and Ag contamination. Both the invertebrates and fish showed positive correlations between Cu and Ag concentrations, indicating similar source and/or uptake route. The target hazard quotients (THQ) show that there is no human health risk associated with the consumption of these fish. However, the levels of Zn, Cd, and Pb in P. ovata surpassed maximum food safety limits and are hence potentially unsafe for human consumption.

Genesis and tectonic setting of Shenshan Fe–Cu deposit in Inner Mongolia, Northeast China: Constraints from geochemistry, U–Pb and Re–Os geochronology, and Hf isotopes

The newly-discovered Shenshan Fe–Cu skarn deposit is located in the southern Great Xing’an Range of northeastern China. The mineralization occurs mainly in the exoskarn or marble wallrocks of the Permian Zhesi Formation, which were intruded by the Shenshan granodiorite and granite porphyry dykes. Molybdenite Re–Os dating yielded a weighted mean age of 160.2 ± 2.4 Ma (MSWD = 0.38), consistent with the LA–ICP–MS zircon U–Pb age of the granodiorite (161.6 ± 2.2 Ma; MSWD = 0.75), but significantly older than the granite porphyry dykes (132.8 ± 1.9 Ma; MSWD = 0.87). This suggests a coeval and causative relationship between the granodiorite and Fe–Cu mineralization. The Shenshan granodiorite has an adakite-like geochemical signature with high Sr contents (704–871 ppm), and high Sr/Y (46.79–80.21) and (La/Yb)N (17.54–31.13) ratios, but low Y (9.7–13.1 ppm) and Yb (0.70–1.18 ppm) contents. The granodiorite has relatively low contents of Mg (1.71–1.94 wt%), Cr (18–23 ppm), and Ni (4.1–9.0 ppm), and positive εHf(t) (−0.3 to 3.0, average 1.51), yielding two-stage model ages (TDM2) of 1.38–1.68 Ga (average 1.51 Ga). The results indicate that the parental magmas of the granodiorite were derived from partial melting of juvenile thickened lower crust with minor mantle-derived input. Meanwhile, the Shenshan granite porphyry dykes are high-K calc-alkalic and weakly peraluminous, with low MgO (0.21–0.24 wt%) and Mg# (19–21). The dykes exhibit HFSE (e.g., Nb, Ta) depletions and LILEs (e.g., Rb, K) enrichments, and strong to moderate negative Eu anomalies, indicating major continental crust-derived input in the magma source. Geochemical and Hf isotopic data compilation for granitoids across the Great Xing’an Range indicate that the mineralization at Shenshan was influenced by the south-dipping subduction of the Mongol–Okhotsk oceanic plate. The discovery of adakite-like rocks in the Shenshan Fe–Cu deposit, and the voluminous adakite-like rocks in the region, suggest that the Mesozoic Great Xing’an Range has considerable prospecting potential for Cu–Au–Mo deposits.

(Invited) Synthesis of Helical-CNT and Stacked Graphene-CNF Using a Copper Foil As Catalyst in a Chemical Vapor Deposition System

Helical carbon nanotubes (H-CNT) and stacked graphene carbon nanofibers (SG-CNF) were synthesized in an aerosol assisted chemical vapor deposition system (AACVD) using a copper foil as catalyst and substrate and ethanol vaporized as precursor. The copper foils were cleaned and pre-treated with ethanol, isopropanol and acetone in sonication bath during one hour each to obtain a slight surface modification. The AACVD was carried in one tubular furnace at 980 °C where several copper foils of 0.25 mm thickness and 4 cm x 1 cm area were placed inside the reactor from the highest to the coolest temperature zone. This carbon nanostructures were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, Raman spectroscopy, atomic force microscopy (AFM) and cyclic voltammetry using a Calomel electrode in a KCl 0.5 M solution as electrolyte. A variety of carbon morphologies were found passing from the growing of graphite at the highest temperature to the formation of the H-CNT and SG-CNF at the temperature dropping zone (figure 1a-1f). Migration of sharp copper nanoparticles (10 nm – 200 nm) was observed as copper nanoparticles were found at the surface covered by carbon materials, while as we go out the furnace, faceted copper nanoparticles are partially covered of graphitic materials. A diminution of the Cu(200) crystalline plane of the copper foil as the temperature decreases is visible and the formation of copper oxide at the farthest position play a significant role in the growing of the carbon nanostructures. The H-CNT are helical structures with no practically gap between each coil with a pitch of ~27 nm by a tubular structure with ~20 graphitic layer in each wall (figure 1g-1i), in the case of the SG-CNF the graphitic layers are almost perpendicular to the CNT axis similar to a stacked short graphene layers directed outwards the structure that leds to the edge formation. Raman characterization illustrates differences between the graphitic carbon structures found at early stages from those at the dropping temperature zone where at the higher temperature mainly graphite the relation of the ID/IG bands is 0.88, while for the H-CNT and SG-CNF the ID/IG relation is 1.79 indicative of high defective graphitic structure which is related with the “herringbone structure” of the SG-CNF, in the case of the coolest zone the Raman spectra is characteristic of low sp3 amorphous carbon (ID/IG of 0.67). The cyclic voltammetry results indicates that the sample with the H-CNT and SG-CNF structures becomes more capacitive in a cuasi-reversible process with practically no modification of the standard oxide-reduction potential for Cu, while for the other sections this oxide-reduction potential increases. Another aspect of the sample with the H-CNT and SG-CNF is its hydrophobic surface with a contact angle of 122 °. With this work we demonstrate that a light surface modification of the copper foil and the temperature profile inside the furnace has a high influence in the formation of the H-CNT and the SG-CNF, also the shape of the copper nanoparticle influence the type of carbon nanostructure catalyzed over the copper substrate. This material could be a good for oxide-reduction reactions. Figure 1

Electrochemical deposition of praseodymium (III) and copper (II) and extraction of praseodymium on copper electrode in LiCl-KCl melts

Cyclic voltammogram and square wave voltammograms indicated that Cu (II) ion being reduced to Cu(0) was a two-electron process: Cu(II) + e− → Cu(I) and Cu(I) + e− → Cu(0). The diffusion activation energy for Cu (I) ions was calculated as 42.85 kJ mol−1. The equilibrium potential and apparent standard potential for Cu (I)/Cu(0) redox couple was measured by open circuit chronopotentiometry at a temperature of 773–923 K. Three reduction peaks, corresponding to the formation of PrxCuy intermetallic compounds, were detected from cyclic voltammogram and square wave voltammogram obtained by co-reduction of Pr (III) and Cu (II) or electrodeposition of Pr (III) on Cu electrode. Furthermore, potentiostatic electrolysis was performed to extract the element Pr on Cu electrode, and the electrolytic products were analyzed by scanning electron microscopy equipped with energy dispersive spectrometry. Meanwhile, the highest extraction efficiency of Pr (III) ions could reach about 99.81% at − 2.20 V for 22 h at 823 K.

Facile Deposition of Cu−SnOx Hybrid Nanostructures on Lightly Boron‐Doped Diamond Electrodes for CO2 Reduction

AbstractIn this work, we report a facile synthesis of Cu−SnOx hybrid nanostructures on lightly boron‐doped diamond (BDDL) electrodes by a potentiodynamic electrodeposition method. The deposition potential for Cu−SnOx hybrid nanostructures was cycled between 0 to −1.0 V vs Ag/AgCl for five consecutive runs at a scan rate of 50 mV/sec. The growth of the Cu−SnOx hybrid nanostructures on BDDL was optimized by varying the number of potentiodynamic deposition cycles and precursor concentration. A uniform particle size distribution of Cu−SnOx was obtained on BDDL using 10 mM CuSO4 and 5 mM SnCl2 in 50 mM aqueous NaNO3. Detail of surface morphology and surface elemental composition of the optimized Cu−SnOx hybrid nanostructures modified BDDL electrodes were characterized. The optimized Cu−SnOx hybrid nanostructures on BDDL were found to be in the size range of 50 to 100 nm with a 3 to 10 nm SnOx‐rich shell. This optimized Cu−SnOx modified BDDL electrode was tested for electrochemical CO2 reduction reaction in aqueous electrolyte and found to produce primarily CO with a Faradaic Efficiency of up to 82.5 % at −1.6 V vs Ag/AgCl.

Embedded atom method potential for studying mechanical properties of binary Cu–Au alloys

We present an embedded atom method (EAM) potential for the binary Cu–Au system. The unary phases are described by two well-tested unary EAM potentials for Cu and Au. We fitted the interaction between Cu and Au to experimental properties of the binary intermetallic phases Cu3Au, CuAu and CuAu3. Particular attention has been paid to reproducing stacking fault energies in order to obtain a potential suitable for studying deformation in this binary system. The resulting energies, lattice constant, elastic properties and melting points are in good agreement with available experimental data. We use nested sampling to show that our potential reproduces the phase boundaries between intermetallic phases and the disordered face-centered cubic solid solution. We benchmark our potential against four popular Cu–Au EAM parameterizations and density-functional theory calculations.

Modification of chitosan/calcium alginate/Fe3O4 hydrogel microsphere for enhancement of Cu(II) adsorption.

Copper in drinking water causes a significant environmental problem. Composite material based on alginate hydrogel has been gaining attention in the field of Cu(II) adsorption. However, alginate-based hydrogel exhibits poor mechanical property and relative low adsorption capacity which limit their application. The present study is devoted to the modification of chitosan/calcium alginate/Fe3O4 (CAF) hydrogel microsphere by NaOH solution for enhancement of Cu(II) adsorption. Results reveal that modification of CAF via NaOH solution significantly improves the mechanical strength and Cu2+ adsorption capacity of pristine materials. FTIR and XRD analysis confirms that CAF and newly prepared materials (NACAF) are successfully prepared. SEM and EDX are employed to analyze the surface morphology and elemental composition, respectively, both before and after their loading with Cu2+. XPS study demonstrates adsorption mechanism is based on chelation and ion-exchange. Compressive stress-strain curves demonstrate NACAF has better mechanical performance than CAF. The adsorption kinetics of the two adsorbents follow a pseudo-second-order model. The equilibrium data were best described by Langmuir isotherm model, and the estimated maximum equilibrium sorption capacity, q m,is 261.31mg/g for the NACAF, which is larger than that of CAF (145.39mg/g). Hence, NACAF shows excellent mechanical strength and high sorption capacity for Cu2+. It has great potential for Cu(II) removal in aqueous solutions.

The Efficient Removal of Heavy Metal Ions from Industry Effluents Using Waste Biomass as Low-Cost Adsorbent: Thermodynamic and Kinetic Models

Abstract The ability of green micro algae Chlorella vulgaris for biosorption of Cu(II) ions from an aqueous solution was studied. The biosorption process was affected by the solution pH, contact time, temperature and initial Cu(II) concentration. Experimental data were analyzed in terms of pseudo-first order, pseudo-second order and intra particle diffusion models. Results showed that the sorption process of Cu(II) ions followed pseudo-second order kinetics. The sorption data of Cu(II) ions are fitted to Langmuir, Freundlich, and Redlich–Peterson isotherms, and the Temkin isotherm. The thermodynamic study shows the Cu(II) biosorption was exothermic in nature. The Cu(II) ions were recovered effectively from Chlorella vulgaris biomass using 0.1 M H2SO4 with up to 90.3% recovery, allowing for recycling of the Cu. Green algae from freshwater bodies showed significant potential for Cu(II) removal and recovery from industrial wastewater.

Evolution of dislocation mechanisms in single-crystal Cu under shock loading in different directions

Even though there are numerous experiments and molecular dynamic simulations of Cu under shock loading, there appears to be no literature on the evolution of different types of dislocation mechanisms and their mutual interactions during the process of shock loading, which this article addresses through molecular dynamic simulations using the Mishin EAM potential for Cu. Three different directions , , and that have been considered in this article are subjected to shock compression with piston velocities ranging between 0.3–3 km s−1. The evolution of Hirth locks, Lomer–Cottrell locks, cross-slips, jogs, and dislocation-originated stacking-fault tetrahedra are demonstrated in this article for different direction shock loading of single-crystal Cu.

Kinetics and isotherm studies for the adsorption of metal ions onto two soil types

Abstract Transport of contaminants from soil to other trophic levels is associated with retention/binding capacity of soil with pollutants. The sorption potential of red and black soils for Cu(II) and Ni(II), respectively was analysed through batch experiments. The batch experiments were conducted to identify equilibrium time, equilibrium adsorbent dosage and equilibrium metal concentration. The kinetics and adsorption isotherms were studied using pseudo-first order and pseudo-second order equation, and Langmuir, Freundlich and Temkin isotherm models. Agitation time, adsorbent dosage and metal concentration played a significant role in the rate of adsorption. The percentage removal of Cu(II) and Ni(II) was higher initially and reached equilibrium after 480 min and 300 min of agitation, respectively. The maximum removal rate for Cu(II) by red soil was 97.3% and for Ni(II) by black soil was 99.9%. The examination of kinetics and adsorption isotherm revealed that the sorption experiments fitted well with the pseudo-second order equation and Freundlich isotherm model, respectively. Thus, red and black soil have significant metal retention potential for Cu(II) and Ni(II), respectively.

Electrochemically synthesized CuInSe2 thin films from non-aqueous electrolyte for solar cell applications

Highly polycrystalline CuInSe2 (CIS) thin films have been electrodeposited from non-aqueous ethylene glycol (EG) solvent on fluorine-doped tin-oxide-coated glass substrates at 130 °C. The co-deposition potential for Cu, In and Se was optimized by using cyclic voltammetry. CIS layers have been electrodeposited from −1.1 V to −1.5 V versus the Ag/AgCl reference electrode. The effect of selenization on structural, morphological, optical and compositional properties has been studied extensively. Highly crystalline CIS thin films are electrodeposited for all reported growth potentials without post-annealing treatment. The Raman spectra of stoichiometric CIS thin films showed a dominant A1 mode with features receptive to the crystalline quality of the layers. Noticeable changes in the surface morphology and composition of films deposited at different deposition potential were observed. All CIS layers were void free, compact, uniform, and well adherent to the substrates with particle size ∼1–3 μm. Both as-deposited and selenized samples were Cu-rich, however, the composition of selenium remained closer to the ideal value, 50%. A typical solar cell prepared at −1.3 V measured VOC = 0.316 V, JSC = 26 mA, FF = 49, and η = 4.2, under illuminated conditions at 100 mW cm−2.

Influence of endophytic Bacillus pumilus and EDTA on the phytoextraction of Cu from soil by using Cicer arietinum

ABSTRACT In developing countries, soil contamination with metals is ubiquitous, which poses a serious threat to the ecosystem. The current study was designed to screen out the nested belongings of Cicer arietinum plants and Bacillus pumilus (KF 875447) in extracting copper (Cu) from contaminated soils. A pot experiment was executed by growing C. arietinum seedlings either inoculated with B. pumilus or uninoculated along with the application of 5 mM ethylenediaminetetraacetic acid (EDTA). Plants were subjected to three different concentrations of Cu (250, 350, and 500 ppm) for 48 days. An increase in Cu uptake was observed in C. arietinum plants inoculated with B. pumilus as compared to uninoculated ones. C. arietinum exhibited improved values for different growth parameters in the presence of B. pumilus, that is, root length (37%), shoot length (31%), whole plant fresh as well as (45%) dry weight (27%), and chlorophyll contents (32%). More than 70% of tolerance index (TI) was observed for plants at 500 ppm Cu treatment. Addition of B. pumilus and EDTA significantly increased metal uptake by C. arietinum up to 19 and 36%, respectively, while the application of B. pumilus and EDTA in combination increased metal accumulation by 41%. The calculated bioaccumulation and translocation factor (TF) revealed that C. arietinum possess phytoextraction potential for Cu, and this ability is significantly improved with application of B. pumilus and EDTA amendments.

Dodecyl sulfate chain anchored mesoporous graphene: Synthesis and application to sequester heavy metal ions from aqueous phase

Herein, graphene (GN) was synthesized, exfoliated by anchoring dodecyl sulfate chain through hydrophobic interaction over its surface (GN-SDS), and was tested to sequester Cu(II) and Mn(II) ions in single-metal system from aqueous phase. Acid-base titrations and elemental analysis results verified successful dodecyl sulfate chain anchoring over GN-SDS surface. Adsorption/desorption isotherms depicted Type-IV isotherm with H3 type hysteretic loop, confirming mesoporous nature of GN-SDS with BET surface area – 242m2/g. The ID/IG ratios of GN and GN-SDS obtained by RAMAN spectroscopy were 0.8537 and 0.8540, respectively confirming no distortion in structure during modification. Electrostatic interaction between metal ions and negative surface charge and-/or Cπ electrons of GN-SDS was governing the adsorption process. Maximum Cu(II) and Mn(II) adsorption on GN-SDS was observed at pH 5 and 6, respectively. Rapid Cu(II) and Mn(II) adsorption kinetics accomplishing 80–92% and 87–96%, respectively at varied concentration in 60min was observed. Maximum adsorption capacities for Cu(II) and Mn(II) on GN-SDS were 369.16 and 223.67mg/g, respectively. Langmuir isotherm and pseudo-second-order kinetic models were fitted to experimental data. Thermodynamically favorable adsorption process was observed. 30–33% drop in GN-SDS adsorption potential for Cu(II) and Mn(II) after five consecutive regeneration cycles was observed.