CuO Compounds Research Articles

A numerical simulation of solar cells based on the CuO and Cu2O absorber layers with ZnMgO window layer

In this paper the software of Solar Sell Capacitance Simulator (SCAPS) is used to study the performance of ZnO:Al /Zn1-xMgxO/CuxO solar cells. As an absorber layer are used CuO and Cu2O compounds. The photovoltaic parameters have been calculated for the samples prepared at different deposition conditions (layer thickness, magnesium concentration in window layer). Simulated current–voltage curves allow to determinate the optimal deposition conditions. As a result of the numerical simulation there were determined the optimal solar cells layers fabrication parameters, which provide their maximal solar energy conversion efficiency. They are: in case of CuO/ZMO/AZO structure - fill-factor is 76.46 %, photo-conversion efficiency is 23.89 %; in case of Cu2O/ZMO/AZO structure – fill-factor is 69.44 %, photo-conversion efficiency is 9.63 %, respectively.

Corrosion behavior and mechanical performance of weathering steel in industrial and rural atmospheric environments

In this study, a series of alternate immersion tests were conducted to simulate the corrosion processes of weathering steel and control material (Q235 steel) in industrial and rural atmospheric environments. The corrosion rates of the two steels were regularly monitored and compared using weight loss method. Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) were employed to analyze the microstructure and phase compositions of the rust layer formed on steel. Finally, the tensile tests were performed to examine the mechanical performance degradation of weathering steel. The results indicated that the corrosion rates of weathering steel decreased dramatically at first and then tended to be steady. In industrial environment, the weathering steel maintains a 30 % lower corrosion rate than Q235 steel, whereas in rural environment, the difference between the two corrosion rates decreased dramatically over time and disappeared after 360 h. The cause for the difference between the corrosion rates is that weathering steel has higher content of α-FeOOH, CuO and Ni compounds in the corrosion product which make its rust layer more compact and denser than that of Q235 steel, leading to better corrosion resistance. Existing stress-strain curve models for ordinary steel gave poor prediction effect in the hardening stage of weathering steel. Therefore, a new constitutive model for the weathering steel was proposed in this study. It is demonstrated that the proposed model can well reflect the mechanical behaviors of weathering steel before and after corrosion.

Control of microbial agents by functionalization of commercial air filters with metal oxide particles

According to the World Health Organization, low-quality air results in 3.2 million premature annual deaths of which 21 % are attributed to respiratory infections. The recent coronavirus (COVID-19) pandemic, responsible for millions of deaths worldwide, has highlighted the issue of airborne pathogens on human health. Air filtration is an established method to ensure good indoor air quality, being effective at capturing airborne particles and dust, as well as pathogens, and preventing diseases such as asthma. Nevertheless, with usage, water from air humidity, dust, and dirt, including fungi and bacteria spores, can accumulate on filters creating ideal conditions for the propagation of microorganisms. Thus, the filter can become a secondary source for airborne pathogens. In this work, antiviral and antibacterial filters were prepared by spray coating Ag2O, CuO, and ZnO particles into commercially available air filters. The reliability of the filters was tested through particle release in air, through a scanning mobility particle sizer, and filtration performance was measured against an aerosol of iron nanoparticles in nitrogen gas produced through a spark discharge generator. Additionally, the biosafety of the filters was measured in vitro through cytotoxicity tests against L-929 mouse fibroblast cells. Antibacterial activity was measured in vitro against two clinically relevant pathogens: Streptococcus pneumoniae and Pseudomonas aeruginosa and the anti-viral performance was measured against human respiratory syncytial virus. In general, the results have shown that spray coating is a reliable solution, with no detectable cytotoxicity effects or particle release in the air. After functionalization, both Ag2O and CuO compounds have been shown to have total antiviral activity (over 99 %), while only Ag2O presented a clear antibacterial action. In conclusion, spray coating as post-manufacturing functionalization of air filters can be an efficient and low-cost solution against airborne pathogens.

Structure, optical and magnetic properties of PVA/CuO/CoFe2O4 nanocomposite films for flexible magneto-electronic applications

Pure polyvinyl alcohol (PVA) and its nanocomposites with CuO and/or CoFe2O4 films have been prepared with different weights of ≤ 5 %. The structure of the films shows an orthorhombic phase of semi-crystalline polymer for PVA, a monoclinic phase for CuO, and a cubic phase of CoFe2O4 in nanocomposite films with particle sizes ≤ 25.5 nm, as determined by the XRD technique. Surface morphology by TEM of representative films shows the crystalline structure and nanoparticles and nanorods of individual CuO and/or CoFe2O4 compounds. The optical transmission and reflection properties of films have been measured, and the optical band gap has been estimated, showing that variable values (1.4–4 eV) can be controlled by controlling the percentage of CuO and/or CoFe2O4 in films. Magnetic investigation shows diamagnetic behavior for PVA and paramagnetic behavior for PC1, PC3, while PC5 has a very weak ferromagnetic response. Whereas nanocomposites with different contents of CoFe2O4 exhibit smooth ferromagnetic behavior with increasing Ms values. Ferromagnetic behavior has been confirmed via a convex Arrott–Belov–Kouvel plot. The improvement of magnetic properties makes the prepared films suitable to be used in various fields, such as antenna system miniaturization and flexible magneto-electronic applications.

Impact of CuO loading for enhanced photocatalytic performance of CdS/CuO photocatalyst on rhodamine 6G dye decomposition under ultraviolet irradiation

In this study, we have incorporated different ratios of copper oxide (CuO) into cadmium sulphide (CdS) to fabricate CdS/CuO binary composites that are utilized as an efficient photocatalyst for rhodamine 6G (R6G) dye decomposition under ultraviolet (UV) exposure. CdS and CuO formed by precipitation and annealing were combined to form composites using a wet physical mixing method. X-ray diffraction (XRD) analysis reveals the preservation of their respective crystalline phases in the composite. Scanning electron microscopy (SEM) images imply that the interface between CuO and CdS improves with increasing CuO content. The coexistence of CuO and CdS compounds could also be verified by Fourier-transform infrared spectroscopy (FTIR) analysis. Also, the UV–Vis absorbance spectra demonstrate a significant increase in absorption intensity accompanied by a bandgap narrowing, which is beneficial for photocatalytic activity. The photocatalytic degradation rate and efficiency are significantly enhanced with CuO loading, with the highest constant rate obtained being as 4.69 × 10-3 min−1. Conclusively, the present CdS/CuO composite can serve as a vital catalyst for environmental sustainability, especially in wastewater remediation.

Room-temperature oxygen vacancy migration induced reversible phase transformation during the anelastic deformation in CuO

From the mechanical perspectives, the influence of point defects is generally considered at high temperature, especially when the creep deformation dominates. Here, we show the stress-induced reversible oxygen vacancy migration in CuO nanowires at room temperature, causing the unanticipated anelastic deformation. The anelastic strain is associated with the nucleation of oxygen-deficient CuOx phase, which gradually transforms back to CuO after stress releasing, leading to the gradual recovery of the nanowire shape. Detailed analysis reveals an oxygen deficient metastable CuOx phase that has been overlooked in the literatures. Both theoretical and experimental investigations faithfully predict the oxygen vacancy diffusion pathways in CuO. Our finding facilitates a better understanding of the complicated mechanical behaviors in materials, which could also be relevant across multiple scientific disciplines, such as high-temperature superconductivity and solid-state chemistry in Cu-O compounds, etc.

CuO/CuxS composites fabrication and their thermoelectric properties

Herein, copper oxide/copper sulfide (CuO/CuxS) composites have been prepared by treating CuO with thiourea by an aqueous hydrothermal route and their thermoelectric properties are studied. The electrical conductivity is improved with the increase in thiourea content, as a result, thermoelectric power factor increased from 10–4 to 101 µW m−1 K−2, and thermal conductivity of the CuO is also found to decrease with thiourea treatment. A detailed analysis indicated that these changes are due to the formation of copper sulfide (CuxS) in the CuO compound; a small fraction of electrically good conducting CuxS in the bulk CuO has produced composites with better electrical conductivity. These low-cost and non-toxic materials can be useful in thermoelectric energy conversion applications.

Chemical, morphological and optical properties of undoped and Cu-doped ZnO thin films submitted to UHV treatment

The undoped and Cu-doped zinc oxide (UZO and CZO) thin films deposited on Si substrate were treated in the UHV (Ultra-High Vacuum) system using Ar+ sputtering followed by a controlled annealing process at 650 °C. The sensitive experimental techniques XPS (X-rays Photoelectron Spectroscopy), REELS (Reflection Electron Energy-Loss Spectroscopy), PL (Photoluminescence) and AFM (Atomic Force Microscopy) have been adopted to characterize the effect of this UHV treatment on the chemical, morphological and optical properties of both samples. The XPS results show the complete removal of contamination species from the surface and bulk for both samples and display the well-defined formation of CuO and/or CuOuZn compounds in the CZO. The AFM images exhibit a significant improvement in the surface morphologies, especially CZO. Through the REELS results, the appearance of CuO oscillator (4.5 eV) at high primary energy proves more incorporation of copper into the bulk ZnO matrix. Besides, the PL measurements reveal a complete disappearance of green emission of UZO and improvement for CZO one. The slight redshift and the broadening of CZO UV-emission confirm the incorporation and substitution of copper into the ZnO matrix. Thus, this treatment is of great interest to improve the surface efficiency for reliable devices.

Effects of the Addition of Cu and Ni on the Corrosion Behavior of Weathering Steels in Corrosive Industrial Environments

The effect of Cu and Ni content on the corrosion behaviors of weathering steels in a corrosive atmosphere was investigated using electrochemical measurement techniques, such as electrochemical impedance spectroscopy and linear polarization resistance methods. Scanning electron microscopy with energy-dispersive spectrometry (EDS) and x-ray diffraction (XRD) were used to analyze the samples. The corrosion rates, which are above 2.0 mm a−1 at 48 h and approximately 1.12 mm a−1 at the range of 144-240 h, show that Cu and Ni slowed down the electrochemical reaction at the initial corrosion stage. With an increasing immersion time, the protective properties of the rust layer exhibited an increase in its impedance, and it was enhanced compared to that in the initial stage. The enrichment phenomenon of Cu and Ni elements in the inner rust layer was more evident in the 0.4Cu-0.4Ni and 0.7Cu-0.7Ni steels than that of 0.3Cu-0.3Ni steel after 240 h. The XRD and EDS results show that the inner rust layer contained compositions of CuO and Ni compounds, which filled up the pores located on the corrosion products contributing to the densification of the rust layer.

Relationship between the Auger parameter and the ground state valence charge of the core‐ionized atom: The case of Cu(I) and Cu (II) compounds

We develop a simple semiempirical model that correlates the Auger parameter to the ground state valence charge of the core‐ionized atom with closed shell electron configuration. Until now, the Auger parameter was employed to separate initial and final state effects that influence the core electron binding energy. The model is applied to Cu(I) and Cu (II) compounds with the Auger parameter defined as α' = EbFL (2p3/2) + EkFL (L3M45M45;1G). The Auger parameter shift for Cu(I) ion in CuI, CuBr, CuFeS2, Cu2S, and Cu2O compounds—with respect to the copper free atom—increases with the electronic polarizability of the nearest‐neighbour ligands suggesting a nonlocal screening mechanism. This relaxation process is interpreted as due to an electron transfer from the nearest‐neighbour ligands toward the spatially extended 4sp valence orbitals of the core‐ionized Cu(I) ion. In agreement with our model, a linear relationship is found between the Auger parameter shift and the ground state Bader valence charge obtained by density functional theory calculations.The Auger parameter shift for the Cu (II) ion in CuF2, CuCl2, CuBr2, CuSO4, Cu (NO3)2•3H2O, Cu3(PO4)2, Cu (OH)2, and CuO compounds is very close to the Auger parameter of metallic copper, and therefore, it is not related to the calculated ground state Bader valence charge. The relaxation process in the final state is dominated by the local screening mechanism, which involves an electron transfer from the nearest‐neighbour ligands toward the spatially contracted 3d orbitals of the core‐ionized Cu (II) ion.

The Effect of Sintering Time on Superconductor Wire Bi-Pb-Sr-Ca-Cu-O with Dopant Te Sheeted Ag Using Powder In-Tube Method

The use of silver and tellurium metals in fabricating superconductor material has been considered as promising materials. These metals are able to improve both mechanical and thermal stability. However, the fabrication of superconducting material is not merely affected by the composition of metals, but also the method in fabricating the material. To understand the effect of both factors, a study is conducted to investigate the effect of sintering time and dopant tellurium covered by silver sheet. The superconducting material was fabricated by powder in tube method composed with bismuth, lead, calcium, gold, and oxygen. The results showed that high time of sintering decreased the critical temperature of the superconducting material for over 20% from 65K to 51K. Morphological display showed that during high time of sintering caused melting of the grain even though the porosity was less. On the other hand, XRD pattern displayed that high time of sintering formed CuO and CaTeO4 compounds considered as impurities. Overall, the length of time affects the superconducting properties including critical temperature and the purity of material.

Effect of Glass Addition on the Phase Formation, Microstructures Evolution and Dielectric Properties of CCTO Ceramics for Energy Storage Capacitor

Effect of glass addition on the phase formation and microstructural evolution of CCTO ceramics for energy storage capacitor was studied. CCTO and CCTO-borosilicate glass based ceramics (0-1 wt.%) were prepared by solid state reaction method. The powders were pressed at 250 MPa and were sintered at 1040 °C for 10 hours. XRD analysis illustrates the formation of CCTO phase with minor peaks of CuO phase for CCTO and CCTO-glass composites samples. The glass were observed to be segregated at the grain boundaries of CCTO alongside with CuO compound. The dielectric properties indicate that both εr and tan δ were reduced after the addition of glass. Thus, it shows that the borosilicate glass addition into CCTO can affect the physical and dielectric properties of CCTO ceramics.

Underlying burning resistant mechanisms for titanium alloy

The “titanium fire” as produced during high pressure and friction is the major failure scenario for aero-engines. To alleviate this issue, Ti-V-Cr and Ti-Cu-Al series burn resistant titanium alloys have been developed. However, which burn resistant alloys exhibit better property with reasonable cost needs to be evaluated. This work unveils the burning mechanisms of these alloys and discusses whether burn resistance of Cr and V can be replaced by Cu, on which thorough exploration is lacking. Two representative burn resistant alloys are considered, including Ti14 (Ti-13Cu-1Al-0.2Si) and Ti40(Ti-25V-15Cr-0.2Si) alloys. Compared with the commercial non-burn resistant titanium alloy, i.e., TC4 (Ti-6Al-4V) alloy, it has been found that both Ti14 and Ti40 alloys form “protective” shields during the burning process. Specifically, for Ti14 alloy, a clear Cu-rich layer is formed at the interface between burning product zone and heat affected zone, which consumes oxygen by producing Cu-O compounds and impedes the reaction with Ti-matrix. This work has established a fundamental understanding of burning resistant mechanisms for titanium alloys. Importantly, it is found that Cu could endow titanium alloys with similar burn resistant capability as that of V or Cr, which opens a cost-effective avenue to design burn resistant titanium alloys.

Microstructure, thickness and sheet resistivity of Cu/Ni thin film produced by electroplating technique on the variation of electrolyte temperature

In this research, it has been made Cu/Ni thin film produced with electroplating technique. The deposition process was done in the plating bath using Cu and Ni as cathode and anode respectively. The electrolyte solution was made from the mixture of HBrO3 (7.5g), NiSO4 (100g), NiCl2 (15g), and aquadest (250 ml). Electrolyte temperature was varied from 40°C up to 80°C, to make the Ni ions in the solution easy to move to Cu cathode. The deposition was done during 2 minutes on the potential of 1.5 volt. Many characterizations were done including the thickness of Ni film, microstructure, and sheet resistivity. The results showed that at all samples Ni had attacked on the Cu substrate to form Cu/Ni. The raising of electrolyte temperature affected the increasing of Ni thickness that is the Ni thickness increase with the increasing electrolyte temperature. From the EDS spectrum, it can be informed that samples already contain Ni and Cu elements and NiO and CuO compounds. Addition element and compound are found for sample Cu/Ni resulted from 70° electrolyte temperature of Ni deposition, that are Pt and PtO2. From XRD pattern, there are several phases which have crystal structure i.e. Cu, Ni, and NiO, while CuO and PtO2 have amorphous structure. The sheet resistivity linearly decreases with the increasing electrolyte temperature.

Synthesis and Physicochemical Properties of Nd‐, Sm‐, Eu‐Based Cuprate High‐Temperature Superconductors

The aim of the research is to create new high‐temperature superconductors (HTS) NdBa2Cu3O7−x, SmBa2Cu3O7−x, EuBa2Cu3O7−x, and Nd1/3Sm1/3Eu1/3Ba2Cu3O7−x based on light rare earth (LRE) metals. The superconducting materials are investigated for microstructural and physicochemical properties. The paper describes the preparation process of substrate powders and the granulation results of the raw material mixtures before the first calcination, as well as after the first and the second calcination. The granulation analysis of the raw materials are performed using a low‐angle laser light scattering (LALLS) method. Qualitative and quantitative phase analysis of the superconducting materials after the first and the second calcination and after annealing in oxygen atmosphere have been performed by X‐Ray diffraction (XRD) technique. A detailed structural investigations mainly shows the orthorhombic phase with small amounts of BaCuO2 and CuO compounds detected in all samples. A microstructural analysis of materials are carried out by using Raman spectroscopy and scanning electron microscopy (SEM), respectively. The magnetic properties of the superconducting materials are characterized by AC magnetic susceptibility as a function of temperature. The critical current densities at liquid nitrogen temperatures were also measured.

Structural and electrochemical characterization of the Ca50Mg20Cu25Zn5 amorphous alloy

The quaternary Ca50Mg20Cu25Zn5 metallic glass in the form of ribbons and plates was successfully fabricated by melt-spinning and copper-mold casting. The structure characterization of the alloy in as-cast state was performed by using X-ray diffraction method. The Reverse Monte Carlo modeling was carried out to obtain structural model of the alloy in the form of ribbon. Moreover, the corrosion behavior of glassy plates was studied by electrochemical measurements and immersion tests in 1, 2 and 3.5% NaCl solution(pH=5.4) at room temperature. As suspected the lowest corrosion activity of the alloy was observed in 1% NaCl solution. The post-corrosion tests were conducted by scanning electron microscopy and energy-dispersive X-ray spectroscopy to examine the corrosion products and chemical composition of the corroded surfaces. The XPS measurements were used to better understand corrosion behavior of the alloy after immersion during the open-circuit conditions. The corrosion surface products were identified to be CaO, MgO, Mg(OH)2 and CaCO3 components. The ZnO and CuO compounds were formed on the surface of glassy samples.

Effect of composition and thermal treatment in catalysts derived from Cu-Al hydrotalcites-like compounds in the NO reduction by CO

In order to minimize the emission of pollutants in the atmosphere copper-based catalysts were studied. This is a cheaper alternative to traditional catalysts, which use noble metals. Catalysts for the NO by CO reduction reaction have been synthesized from Cu-Al type hydrotalcite with different compositions. The influence of thermal treatment at high temperatures, and the atmosphere of the pretreatment before catalytic tests, were also investigated. The characterization by chemical analysis, X-ray diffraction and thermal analysis indicated that pure hydrotalcite was obtained in the precursor with low Al/(Al+Cu) ratio, and that the catalysts were composed of mainly crystalline CuO and amorphous aluminum compounds. Temperature programmed reduction and in-situ XANES showed that some species of Cu+ are present in the catalyst with 50:50 Cu:Al. After thermal treatments, CuO and copper aluminate were formed. All catalysts showed a very good performance, with conversion of 100% in most of them. The catalyst with the least N2O yield was the 50:50 Cu:Al. The corresponding precursor (50:50 Cu:Al) treated at 900°C for 12h improved clearly the activity, and when it was in-situ reduced (before catalytic test) it was most active in comparison to the other catalysts that were evaluated.

Identification of possible sources of atmospheric PM10 using particle size, SEM-EDS and XRD analysis, Jharia Coalfield Dhanbad, India.

Identification of responsible sources of pollution using physical parameter particulate matter (PM)10 in a critically polluted area is discussed in this paper. Database was generated by Ambient Air Quality Monitoring (AAQM) with respect to PM10 and PM2.5 in 18 monitoring stations at Jharia coalfield as per the siting criteria (IS: 5182, Part XIV) during 2011 to 2012. Identification of the probable sources of PM10 was carried out through particle size, shape, morphology analysis (scanning electron microscopy (SEM)), suitable compounds (X-ray diffraction (XRD)) and elements (energy-dispersive spectroscopy (EDS)). Monitoring stations nearby opencast mine were affected by the big-sized and irregular-shaped particles; on the other hand, monitoring stations nearby city were affected by the small-sized and regular-shaped particles. In a city area, additional sources like diesel generator (DG) set, construction activities, coal burning, etc., were identified. Blistering effects were also observed in the particles from mine fire-affected areas. Using the X-ray diffraction technique, presence of FeS2, CuO, FeSO4 and CuSO4 compounds was observed, which indicates the effects of mine fire on particulate emission due to presence of SO4(2-) and S2- ions.

Green synthesis of bi-component copper oxide composites and enhanced photocatalytic performance

A facile and green route was proposed for the synthesis of bi-component copper oxide composite without any templates and additives. The effects of D-(+)-glucose amount, reaction temperature, and reaction time on the morphology and constitution of the products were investigated by SEM, X-ray diffraction, and UV-vis DRS in detail. The results indicate that a series of Cu2O–CuO bi-component copper oxide composites with various morphologies can be easily obtained. Structure characterisation and photocatalytic tests show that the bi-component Cu2O–CuO composites exhibited better photodecolouration of methylene blue than those of the Cu2O, CuO, and Cu–CuO compounds owing to the existence of the synergistic effect between the CuO and Cu2O.

Influences of Copper Complexes on the Properties of MAO Ceramic Coating on Titanium Alloy Surface

The present work focuses on the influence of copper complexes in the MAO electrolyte on the structure and wears resistance of ceramic coating on the surface of titanium alloy. The coatings composition and the morphologies were characterized using X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). It is shown that the working voltage of MAO reaction was lower after adding [Cu (NH3)4]2+ than adding EDTA-Cu. The color of ceramic coating is black (prepared in the electrolyte with [Cu (NH3)4]2+) and brown (prepared in the electrolyte with EDTA-Cu). The black coating contained rutile TiO2, anatase TiO2 and aluminium titanate (Al2TiO5), while the brown coating contained rutile and anatase only. The black coating which contained CuO compound was found to outperform brown coating in wear resistance.