Effect Of Cu Concentration Research Articles

Efficient removal of amoxicillin, ciprofloxacin, and tetracycline from aqueous solution by Cu-Bi2O3 synthesized using precipitation-assisted-microwave

This study investigates the synthesis and characterization of Cu-Bi2O3 for degradation of antibiotics AMX, CIP, and TC using precipitation-assisted-microwave method at varying concentrations of Cu at 0%, 2%, 4%, 6%, and 8%. The effect of Cu concentration on the structural, morphological, and optical properties were studied by XRD, UV-Vis, and SEM-EDX. The optimal results were obtained by adding 4% Cu to the Bi2O3 matrix. With an energy band gap of 2.32 eV, a crystal size of 37.04 nm, and ?-Bi2O3 and CuBi2O4 phases. The removal efficiency of each antibiotic using the photocatalytic method varies, with AMX at 52.06%, CIP at 61.72%, and TC at 69.44%. Cu-Bi2O3 degraded TC-type antibiotics more rapidly. The high removal efficiency and rapid reaction rate indicate that Cu-Bi2O3 is an effective antibiotic removal agent. This further confirms the fact that the addition of Cu to Bi2O3 material can increase its ability to degrade antibiotics more effective.

Effects of Cu concentration on microstructure and tensile properties of high-Zn-content Al–Zn–Mg–Cu alloys

The effects of Cu concentration on microstructure and tensile property of the Al-18Zn-xCu-2.0Mg-0.12Ti-0.4Zr-0.25Sc-0.25Y (x=0.5 wt%, 1.0 wt%, 2.0 wt%) alloys were investigated. The results showed that the precipitation process from the GP zone to η was expedited with increasing Cu concentration, necessitating careful control to enhance the material properties. Optimizing the Cu concentration can lead to superior tensile properties. The alloy with 0.5 wt% Cu exhibited a high tensile yield strength of 626 MPa and a 6% elongation.

Unconventional order/disorder behaviour in Al–Co–Cu–Fe–Ni multi-principal element alloys after casting and annealing

The effect of Cu concentration on the order/disorder behaviour of the AlCoCuxFeNi (x = 0.6 to 3.0) multi-principal element alloys was investigated. BCC and/or FCC phases were observed in the microstructures of the alloys after casting and annealing at 1050 °C followed by slow cooling. Interesting is that the alloys form ordered structures after casting and disordered structures after annealing and slow cooling, while the opposite would be expected. The ordering in the as-cast state is explained by the strong affinity of Al to transition metals, which results in the formation of supercell structures having sublattices occupied by certain elements only. Disordering after annealing has two reasons. Either the phase is composed of nearly pure element (Cu) and is disordered by default or it is composed of randomly distributed nano-segregated regions within a single phase resulting in a uniform distribution of all elements in the sublattices and therefore appearing to be macroscopically disordered. The reason for the formation of such nano-segregated areas might reside in the reduction of Gibbs free energy due to the annealing by the interplay between enthalpy and entropy.

Enhanced nanocrystalline stability of BCC iron via copper segregation

Nanocrystalline alloys are known for their high density of grain boundaries (GBs), which results in low thermal stability and a tendency for coarsening. In this work, we investigated Fe–Cu alloys to explore the effects of Cu concentration on the thermal stability of nanocrystalline samples. Using hybrid molecular dynamics (MD) and Monte Carlo (MC) simulations, annealing treatments of nanocrystalline samples with varied Cu concentrations were conducted. The simulation results revealed that Cu atoms tended to accumulate at GBs. Subsequently, the model with Cu segregation was subjected to mechanical creep loading at various temperatures. Through the analysis of atomic structure evolution during creep deformation, it was found that Cu segregation efficiently stabilizes GBs and restricts their movement. The present findings highlight that the thermal stability of nanocrystalline Fe–Cu alloys can be effectively improved by introducing suitable Cu segregation at GBs.

Effect of Cu concentration on high-temperature mechanical properties and microstructures of Al-Si alloy for forging fabricated by continuous casting process with the heat-insulating-mold

Al-Si alloy billets with 0, 2, 4, and 6 mass%Cu have been fabricated by the Heat-Insulating-Mold method. The microstructures and high-temperature mechanical properties at 423 K, 523 K, and 623 K have been investigated. Increasing Cu concentration changed the types of constituent particles and increased their area fraction. 0.2% proof stress (σ0.2) and ultimate tensile strength (σUTS) increased with increasing Cu concentration at each temperature. SEM observation showed that precipitates increased with increasing Cu concentration and remained in the matrix below 523 K but dissolved into the Al matrix at 623 K. The former suggested that the precipitates contributed to the strength below 523 K. On the other hand, significant work-hardening was confirmed until 0.2% strain at 623 K, which suggested that the constituent particles contributed to the strength just like particle-reinforced composites. The work-hardening rate and the amount of work-hardening increased with increasing Cu concentration and correlated with the interparticle spacing of the constituent particles. It indicated that decreasing interparticle spacing enhanced constraining matrix deformation, and it led to an increase of σ0.2 and σUTS.

Fabrication, structural, morphological, and optical studies of CdS:Cu nanostructured thin films: effect of Cu concentration

Fabrication, structural, morphological, and optical studies of CdS:Cu nanostructured thin films: effect of Cu concentration

High-precision copper isotopic analysis using a Nu Sapphire MC-ICP-MS

Cu isotopic measurements using a Nu Sapphire CC-MC-ICP-MS.

Effect of Cu on the strengthening and embrittling of an FeCoNiCr-xCu HEA

The effect of Cu concentration on the microstructure and mechanical properties of FeCoNiCr- x Cu HEAs was investigated. The results showed that low Cu concentrations (less than ∼5 at. %) contributed to a solid solution strengthening effect. The solid solution Cu atom strengthened the yield strength and ultimate tensile strength together. When the Cu concentration reached approximately 7 at. %, larger numbers of nano Cu-rich particle precipitated from the FCC matrix. The nano Cu-rich particle had a strengthening effect and further increased the yield strength and ultimate tensile strength. When the Cu concentration reached approximately 13 at. %, the weak continuous Cu-rich phase formed between dendrites. The early fracture of the Cu-rich phase dramatically decreased the ultimate tensile strength and elongation.

Ag NP catalysis of Cu ions in the preparation of AgCu NPs and the mechanism of their enhanced antibacterial efficacy

Aqueous dispersions of AgCu nanoparticles (NPs), with enhanced antibacterial efficacy, have been prepared through the catalyzed reduction of Cu ions by PVP/PVA-stabilized Ag nanoparticles at 85 °C. The effects of Cu concentration and heating time on NP morphology and antibacterial efficacy were investigated, using TEM, UV-Vis and FTIR spectroscopies, and antibacterial evaluations. The enhanced antibacterial performance of these NPs was correlated with Ag ion release. We propose a simple model of AgCu NP formation, and an enhanced antibacterial efficacy mechanism involving Ag ion release, in which AgCu NPs formation plays a role to control of Ag ion release.

Effect of Cu Concentration on the Selective Catalytic Reduction of NO with Ammonia for Aluminosilicate Zeolite SSZ-13 Catalysts

Effect of Cu Concentration on the Selective Catalytic Reduction of NO with Ammonia for Aluminosilicate Zeolite SSZ-13 Catalysts

Influence of Cu‐Doping on Linear and Nonlinear Optical Properties of High‐Quality ZnO Thin Films Obtained by Spin‐Coating Technique

To study the effect of Cu concentration on morphological, structural, linear and nonlinear optical properties, copper‐doped ZnO thin films are grown by sol–gel/spin‐coating technique on the glass substrates. Scanning electron microscopy (SEM) images reveal that the surface morphology is homogeneous with good adhesion to the glass substrate. The energy dispersive X‐ray spectroscopy (EDS) spectra confirm that Zn, O, and Cu elements are present in ZnO films. The X‐ray diffraction (XRD) pattern of Cu‐doped ZnO is dominated by (002) peak, indicating an upstanding ZnO nanorods array growing along the c‐axis. The optical bandgap of Cu‐doped ZnO thin films, calculated from optical transmission spectra, is found to decrease with the increase in copper concentration. The refractive index dispersion curve of ZnO films is subjected to the single‐oscillator model. The optical dispersion parameters Eo, Ed, and n∞, the nonlinear refractive index, and nonlinear optical susceptibility are calculated and interpreted.

Structural, electrical and optical properties of Zn1−xCuxO (x = 0.00–0.09) nanoparticles

Pure and copper doped zinc oxide nanoparticles (Zn1−xCuxO) of different concentrations (x = 0.0, 0.03, 0.06 and 0.09 wt%) were synthesized by using co precipitation method. During the next phase, effect of Cu concentration on structural, electrical and optical properties of ZnO-NPs were investigated with the multiple techniques like XRD, UV–visible spectroscopy, FTIR, and two probe methods. The XRD analysis confirmed hexagonal wurtzite crystal structure having crystallite sizes ranging between 18.3 and 24.2 nm. Rotational and vibration mode of different functional groups (OH, CH, C = O and ZnO) were calculated using FTIR spectra. Moreover, the UV visible spectroscopy identified a band gap (3.10–2.30 eV) of pure and Cu doped ZnO-NPs. Finally, electrical properties like conductivity was increased and whereas, the resistivity decreased with increasing Cu dopant concentrations. Overall, addition of Cu as doping agent improved the structural, optical and electrical properties ZnO-NPs and could enable multiple further potential applications like solar cell, energy storage and other optoelectronic devices.

Comparing the effect of Cu-based fungicides and pure Cu salts on microbial biomass, microbial community structure and bacterial community tolerance to Cu

The effect of Cu on three different microbial endpoints was studied using different Cu sources, in order to check the usefulness of pure Cu salts to estimate the toxicity of commercial Cu fungicides on soil microbes. Cu additions caused similar dose-response curves of substrate induced respiration (SIR) decreases regardless of Cu source, i.e. the use of pure Cu salts to estimate the effect of Cu fungicides on microbial biomass using SIR may be useful. Phospholipid fatty acid (PLFA) analysis showed that the Cu source was more important for the microbial community structure than Cu concentration. Thus, the use of Cu salts to infer the effects of Cu fungicides on microbial community structure using PLFA analysis is not recommended, since effects of Cu concentration will be confounded with Cu source. Analyzing pollution induced community tolerance (PICT) to Cu showed that the use of pure Cu salts may overestimate Cu effects if Cu salt additions modified the soil pH. The highest doses of Cu salts increased bacterial community tolerance to Cu between 300 and 600 times, while commercial Cu fungicide increases were between 20 and 160 times. Therefore, the use of pure Cu salts to estimate the Cu fungicides effects on soil microbes is not recommended for PLFAs analyses, not suitable for PICT at high Cu concentrations, while useful for SIR.

Effect of Cu concentration and dopant site on the band gap of MoS2: A DFT study

Density functional theory (DFT) calculations have been performed to investigate the structural and electronic properties of molybdenum disulfide (MoS2) by doping a varying concentration of Cu as impurity. Additionally, substitutional site importance has also been elaborated. The results indicate that Cu doping can significantly modify the structural and electronic properties of MoS2. Replacement of single S atom with Cu atom reduces the band-gap to 1.04 eV relative to 1.95 eV of the pristine material. Adopting different arrangements of Cu atoms employing substitutional doping technique we computed a variety of band-gap values varying from 0.14 to 1.95 eV. The PDOS calculations allow us to speak that foreign impurity Cu forms good chemistry with host MoS2. Thus with variant concentration of impurity, band-gap of MoS2 can be tuned to a certain desired level making 2D MoS2 a suitable material for such electronic applications where band-gap is required similar to semiconducting materials.

Structural and electro-optical properties of electrospun Cu-Doped ZnO thin films

Pure and Cu-doped ZnO thin films (TFs) were synthesized on glass substrates via the electrospinning method, and the effects of Cu concentration on electro-optical and structural properties were investigated. The nanofibers (NFs) changed to cross-linked nanoparticles (NPs) via calcination at 400 °C. XRD results indicate that Cu2+ was successfully incorporated into the ZnO host to form a hexagonal wurtzite structure. The crystallography of Cu-doped ZnO (CZO) was systematically investigated; it was found that both c/a ratio and compressive lattice strain increased. The photoluminescence (PL) behavior of CZO TFs revealed that the excitonic and redshifted UV emissions were manipulated by Zni, Oi, VZn, OZn and VO defect states. Optical absorption measurements showed excellent transmission percentages (above 87%) in the visible light range. The optical band gap of ZnO TFs decreased from 3.3 eV to 3.2 eV after incorporation of Cu. The results of this study show that electrospun CZO TFs has immense potential for use in electro-optical applications.

Preparation and Characterization of Developed CuxSn1-xO2 Nanocomposite and Its Promising Methane Gas Sensing Properties.

Novel materials with nanostructures are effective in controlling the physical properties needed for specific applications. The use of active and sensing materials is increasing in many applications, such as gas sensing. In the present work, we attempted to synthesize incorporated Cu2+ into the SnO2 matrix as CuxSn1−xO2 nanocomposite using a cost-effective precursor and method. It was observed that, at low concentrations of copper precursor, only SnO2 phase could be detected by X-ray diffraction (XRD). The distribution of Cu in the SnO2 matrix was further measured by elemental analysis of energy-dispersive X-ray (EDX) mapping and X-ray fluorescence (XRF). At high copper concentration, a separated monoclinic phase of CuO was formed (noted here as CuO/SnO2). The average crystallite size was slightly reduced from 5.9 nm to 4.7 nm with low doping of 0.00–5.00% Cu but increased up to 15.0 nm at high doping of 10.00% Cu upon the formation of separated SnO2 and CuO phases. The formation of Cu–SnO2 or CuO phases at low and high concentrations was also observed by photoluminescent spectra. Here, only the emission peak of SnO2 with a slight blueshift was recorded at low concentrations, while only the CuO emission peak was recorded at high concentration. The effect of Cu concentration on the sensing properties of SnO2 toward methane (CH4) gas was also investigated. It was found that the sensor embedded with 2.00% Cu exhibited an excellent sensitivity of 69.0 at 350 °C and a short response–recovery time compared with the other sensors reported here. The sensing mechanism of CuxSn1−xO2 and CuO/SnO2 is thus proposed based on Cu incorporation.

Effect of Cu concentration on the interfacial reactions between Sn-xCu solders and Cu substrate

In this paper, the effects of Cu content on the interfacial reactions of Sn-xCu/Cu solder joints were systematically investigated. The examined Cu compositions varied from 0.98 wt% to 11.62 wt%. The reflow and aging processes were performed on Sn-xCu/Cu couples at 280 °C and 180 °C, respectively. Experimental results indicated that the microhardness of as-solidified Sn-xCu solder alloys increased obviously with increasing Cu content. After reflowing, the classical reaction products, Cu6Sn5 and Cu3Sn, were found at the interface of Sn-xCu/Cu couples. The size of Cu6Sn5 grain increased slightly and Cu6Sn5 layer surface also gradually changed from sawtooth-type to scallop-type when the Cu content increased in solder (from 0.98 wt% to 11.62 wt%). Moreover, with extended aging time, the total IMC layer thickened and the morphologies of the Cu6Sn5 IMC layer gradually transformed from scallop-type to planar-type during the thermal aging process. The thickness of Cu3Sn layer also increased with the increase of aging time, as well as the increase of Cu content in solder alloy.

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.

Influence of Cu content on physical characterization and optical properties of new amorphous Ge–Se–Sb–Cu thin films

The present work aims to theoretically study the effect of Cu concentration through many physical parameters, including coordination number (CN), constraints number (CON), overall mean bond energy and cohesive energy (CE), for Ge25Se65Sb10−xCux (where x = 0, 2.5, 5, 7.5 and 10 at%) glasses. As well, the optical constants of the thin films were evaluated via the use of the Swanepoel technique. As the Cu concentration rises, it is found that CN, CON, and CE also rise. This relationship demonstrates the obvious evidence for incremental rigidity of the Ge25Se65Sb10−xCux glasses with the addition of Cu. The chemical bonds anticipated within the glasses were estimated. It was revealed that the heteropolar bonds occurred in the examined glasses are Cu–Se, Ge–Se and Sb–Se, which have energies of 62.425, 49.441 and 43.981 kcal mol−1, respectively. The acquired estimations of the refractive index (n) of the films were fitted to the two-term Cauchy dispersion equation to get the single oscillator (Eo) and dispersion (Ed) energies. In addition, the estimations of the absorption coefficient (α) were acquired using the conditions suggested by Connell and Lewis. An energy gap (Eg) decrement from 1.79 to 1.47 eV was prompted by a Cu concentration rise from 0 to 10% at%.

Prediction of stable Cu-Li binary intermetallics from first-principles calculations: Stoichiometries, crystal structures, and physical properties

Towards a resolution of the longstanding controversy regarding the existence of Cu-Li intermetallic compounds, we extensively investigate the phase stability of Cu-Li intermetallics with various possible stoichiometries at zero temperature and pressure using a global structure searching method. It is found that Cu-Li intermetallics can exist stably at atmospheric pressure, and three stable phases (Fmmm Cu1Li2, Fd3¯m Cu2Li1, and P1¯ Cu7Li1) are identified. Electronic structure analysis reveals that although they are metallic, covalent Cu-Cu and ionic Cu-Li bonds are found in the three structures. Moreover, the 3d states of copper atoms are mostly responsible for bond formations in the stable phases predicted. For all the predicted Cu-Li intermetallics, the effect of Cu concentration on structure, mechanical and thermodynamic properties are calculated systematically. It is found that the copper atoms in Cu-Li intermetallics trend to form covalent bonds, so more covalent bonds are formed as Cu content increases, leading to the increases in the elastic moduli, Vicker hardness and Debye temperature with Cu content on the whole. The Poisson's ratios of Cu-Li intermetallics vary in the range of 0.25 and 0.35, and most of Cu-Li intermetallics exhibit an excellent ductile property. The elastic anisotropy calculations suggest that all the Cu-Li intermetallics show anisotropic elasticity more or less, and the percentage anisotropy in compressibility is smaller than that in shear for each of the predicted Cu-Li compounds.