Copper Oxide Research Articles

Glass ceramics with different colours from granite wastes prepared by changing crystallisation temperature: Crystallisation and properties

Granite is a popular natural decorative material, and its production generates large amounts of waste. Therefore, researchers have paid close attention to the utilization of granite waste as a resource. In this work, glass-ceramic containing the same concentration of copper oxide were prepared from granite waste using a melting technique. The effects of different crystallisation temperatures on the valence of copper ions and the crystallisation of the glass-ceramics were carefully examined. The glass-ceramics crystallised at 724 °C, 783 °C, and 904 °C contained copper oxide (CuO), diopside (CaMgSi2O6), and clinoenstatite (MgSiO3). Meanwhile, those crystallised at 987 °C and 1080 °C contained richterite ((Na, F)syn (Na(Na, Ca)Mg5Si8O22F2)) and cuprite (Cu2O). The crystallisation temperature influenced the valence state of copper ions in the glass-ceramics, as demonstrated by X-ray photoelectron spectroscopy (XPS). Not only was the Cu+ content heterogeneous among samples crystallised at the different temperatures heterogeneous, but the samples also exhibited dissimilar colours. The atomic percentage of Cu+ ions (ACu+) in the sample crystallised at 987 °C was higher than that in the other samples. The mechanical properties of the sample crystallised at 1080 °C included a bending strength of 127.14 MPa and a Vickers hardness of 8.16 GPa.

Versatile performance of hydrophilic PVDF/CuO nanocomposite membranes for TDS removal in RO reject

ABSTRACT In the current study, by using the phase inversion process, PVDF/CuO nanocompositmembranes with diversified concentrations of copper oxide (CuO) nanoparticles were fabricated to reduce the TDS in RO reject. Consequently, compared to pure PVDF membrane, the hydrophilicity of PVDF membrane bearing 2 wt% of chemically synthesized CuO nanoparticles is higher. This was justified through the contact angle which diminished from 110.9° to 58.2°. The improved hydrophilicity, porosity, and pore size are the vital drivers for the fabricated nanocomposite membranes to exhibit an 81% surge in pure water flux and a 75% rise in permeate flux. Fouling of PVDF/CuO nanocomposite membranes was mitigated by incorporating CuO nanoparticles, decreasing the surface roughness. The antifouling capabilities of the fabricated nanocomposite membranes are enhanced by a higher flux recovery ratio of 97.28. Additionally, the outcomes demonstrated that the nanocomposite membrane performs better in TDS removal, with 89% efficiency in RO reject. Thus, the PVDF/CuO nanocomposite membrane has great prospects in applications necessitating the filtration process.

New Method to Recover Activation Energy: Application to Copper Oxidation

The calculation of the activation energy helps to understand and to identify the underlying phenomenon of oxidation. We propose a new method without any a priori hypothesis on the oxidation law, to retrieve the activation energy of partially and totally oxidized samples subject to successive annealing. The method handles the uncertainties on the measurement of metal and oxide thicknesses, at the beginning and at the end of the annealing process. The possible change in oxidation law during annealing is included in the model. By using an adapted Particle Swarm Optimization method to solve the inverse problem, we also calculate the time of final oxidation during the last annealing. We apply the method to successive annealings of three samples with initial nanometric layers of copper, at ambient pressure, in the open air. One, two and three successive laws are recovered from experimental data. We found activation energy values about 105–108 kJ mol−1 at the beginning of the oxidation, 76–87 kJ mol−1 at the second step, and finally 47–59 kJ mol−1 in a third step. We also show that the time evolution of copper and oxide thicknesses can also be retrieved with their uncertainties.

Synthesizing, characterizing, and cold plasma treating of Cr2O3/CuO nanomaterials doped PMMA/PEO for flexible optoelectronic applications

Polymeric nanocomposites are attracting significant attention due to their ability to facilitate innovative uses. This work investigated the possibility of improving performance by examining the impact of dispersing copper oxide (CuO) and chromium (III) oxide (Cr2O3) nanoparticles in a blend of poly (methyl methacrylate) and polyethylene oxide (PEO) on several properties. UV–visible and photoluminescence spectroscopies were used for optical properties, and FE-SEM was used for surface morphology analysis. The results showed that as the CuO–Cr2O3 percentage increased, the extinction coefficient increased, and indirect band gaps decreased. The photoluminescence properties showed two distinct peaks (dual emission). We measured the AC electrical properties with frequencies ranging from 100 Hz to 5 MHz. The composite's AC conductivity and dielectric loss increased significantly at high frequencies (higher than 2 MHz). The dielectric constant is nearly frequency-independent and increases as the concentration of nanoparticles increases. We used a DC plasma sputtering facility to treat the nanocomposites with argon plasma at a pressure of 0.12 mBar for 7 min. We analyzed the films' properties before and after plasma treatment, observing a significant impact on nanocomposite-incorporated nanoparticles. After plasma treatment, the band gap decreased from 5.05 eV to 4.8 eV for the lowest concentration of CuO + Cr2O3 (1.5 wt%) and from 3.55 eV to 2.47 eV for the highest concentration of CuO + Cr2O3 (6 wt%). The changes ranged from 0.25 to 1.08 eV. The films possess features that render them suitable for high-frequency optoelectronic devices as well as optical applications such as emission filters and UV shielding.

Microfluidics assisted green synthesis of copper oxide nanoparticles from the aqueous leaf extract of Ipomoea quamoclit L. with its antimicrobial and antioxidant activity

IntroductionGreen nanosynthesis of medicinal plants are useful for the development of antibiotic agents. In this work, we have explored the antimicrobial and antioxidant activity of green synthesised copper oxide (CuO) nanoparticles (NPs) from tropical medicinal plant Ipomoea quamoclit L. MethodsWith the aid of microfluidic technology, a low-cost, polydimethylsiloxane (PDMS) lab-on-chip micromixer for green nanosynthesis of CuO nanoparticle using Ipomoea quamoclit is presented. The UV–Vis characteristics, Fourier Transform Infra-red (FTIR) spectrum, antimicrobial and antioxidant response using DPPH and hydrogen peroxide (H2O2) were reported. The antimicrobial efficacy of the synthesised CuO-NPs is tested against two-gram positive bacteria Staphylococcus aureus, Micrococcus luteus, two gram negative bacteria, Enterobacter cloacae, Klebsiella pneumoniae and two fungi species Candida albicans, Aspergillus niger. ResultsUV–Vis spectrum for the synthesised CuO-NPs showed the absorbance at 670 nm, scanning electron microscope (SEM) image analysis and dynamic light scattering (DLS) analysis confirmed the presence of spherical shaped nanoparticle sized between 65 and 94.5 nm. The presence of bioactive functional groups of N-H, C-H and C=0 stretching was identified using Fourier Transform Infrared spectroscopy (FTIR). The maximum mean zone of inhibition obtained was 10.45±0.25 mm for fungi A. niger. The antioxidant activity using DPPH scavenging assay and hydrogen peroxide scavenging assay showed the IC50 value 33.94 μg/ml and 42.54 μg/ml respectively. ConclusionsThe obtained results reveal the potential of CuO-NPs synthesised from I. quamoclit L. as a remarkable medicinal entity for wound healing, respiratory infection, fungal infection and urinary tract infection along with the improved antimicrobial and antioxidant activity.

Metallic and metallic oxide nanoparticles toxicity primarily targets the mitochondria of hepatocytes and renal cells.

Nanoparticles (NPs) are utilized in various applications, posing potential risks to human health, tissues, cells, and macromolecules. This study aimed to investigate the ultrastructural alterations in hepatocytes and renal tubular cells induced by metallic and metal oxide NPs. Adult healthy male Wistar albino rats (Rattus norvegicus) were divided into 6 (n = 7) control and 6 treated groups (n = 7). The rats in the treated groups exposed daily to silver NPs, gold NPs, zinc oxide NPs, silicon dioxide NPs, copper oxide NPs, and ferric oxide NPs for 35 days. The members of the control group for each corresponding NPs received the respective vehicle. Liver and kidney tissue blocks from all rats were processed for Transmission Electron Microscopy (TEM) examinations. The hepatocytes and renal tubular cells of all NPs-treated rats demonstrated mitochondrial ultrastructural alterations mainly cristolysis, swelling, membrane disruption, lucent matrices, matrices lysis, and electron-dense deposits. However, other organelles demonstrated injury but to a lesser extent in the form of shrunken nuclei, nuclear membrane indentation, endoplasmic reticulum fragmentation, cellular membranes enfolding, brush border microvilli disruption, lysosomal hyperplasia, ribosomes dropping, and peroxisome formation. One may conclude from the findings that the hepatocytes and the renal tubular cells mitochondria are the main targets for nanoparticles toxicity ending in mitochondrial disruption and cell injury. Further studies taking into account the relation of mitochondrial ultrastructural damage with a weakened antioxidant defense system induced by chronic exposure to nanomaterials are needed.

Fabrication of Bi‐Functional Samarium Oxide/Copper Oxide Nanocuboid Electrocatalyst for Electrochemical Water Splitting

The development of low‐cost, high‐performance electrocatalysts for the oxygen evolution reaction (OER) is essential for a vast array of chemical and energy transformation applications. Using non‐platinum metals as electrocatalysts in a key process such as OER has become increasingly attractive given their relatively low cost, high electrocatalytic activity, and low environmental impact. Herein, to achieve a better catalytic material with high permeability and mass charge transfer in a catalytic framework, a novel, oxygen‐defective Sm2O3/CuO nanohybrid with nanocuboid architecture is developed. The creation of a new composite material which consist of samarium oxide and copper oxide, demonstrates high effectiveness in the process of electrochemical water splitting. The combined use of samarium oxide and copper oxide improves the electrocatalytic performance, stability, and durability due to it synergistic effect. In alkaline media, the Sm2O3/CuO nanocomposite exhibits an astonishing overpotential of 248 mV along with a lower Tafel value of 46 mVdec−1 for OER and nanocomposite also exhibits acceptable hydrogen evolution reaction (HER) performance. Due to the unprecedented porous nanocuboid morphology and the strong synergistic effect between the two materials, the oxygen‐defective Sm2O3/CuO composite exhibits impressive electrical properties and performs exceptionally well as an electrocatalyst for intrinsic water splitting. At an operational potential of 0.5 V, porous Sm2O3/CuO displays outstanding reactivity, Sm2O3/CuO exhibits remarkable results during electrochemical operation.

Yttrium cuprates modification in linear generator application for power generation

Abstract Yttrium barium copper oxide (YBCO) is used for special applications in linear generators because of its excitation loss, lower weight, and higher efficiency. These qualities enable the compound to operate better than the conventional copper wire coil in the stator unit of the linear generator. However, the continuous use of YBCO in linear generators has a fundamental challenge that affects industrial production and material stability after prolonged use. This paper seeks to sustain the adoption of YBCO by improving its quality for linear generator applications. The yttrium cuprates modification (YBYbCO) was synthesized using the solid-state reaction technique by doping YBCO with ytterbium. The crystalline structure, microstructural pattern, and stability of the new sample were adequately measured and found to be structurally stable to ensure durability. It was reported that applying YBYbCO in the linear generator would lead to a 200% increase in energy generation. The higher number of particles and lower individual particulate resistance enable it to withstand chemical pressure, thereby prolonging the lifespan of the linear generator.

Green synthesis of copper oxide nanoparticles using Ficus racemosa leaf extract and investigation of its antibacterial properties

ABSTRACT The present work reports a one-pot green synthesis of copper oxide nanoparticles (CuO NPs) using Ficus racemosa leaf extract via a green chemistry approach without using any harsh chemical reagents. The crystalline and single-phase CuO NPs were analysed via XRD. DLS revealed the average particle size distribution, and zeta potential was used for the evaluation of surface charge. Optical properties were determined at 530 nm through UV–Vis spectroscopy with a broad peak in the range from 500 to 590 nm. Different functional groups in the leaf extract containing flavonoids and polyphenols as reducing agents responsible for the synthesis of CuO NPs were verified through FTIR. The FESEM images revealed the average particle size in the range from 30 to 300 nm with a spherical morphology, and EDS was used for the quantitative elemental analysis. The strong bacterial inhibition tendency of CuO NPs against 12 bacterial strains including Bacillus cereus, Campylobacter jejuni, Bacillus subtilis, Clostridium perfringens, Staphylococcus aureus, Escherichia coli, Streptococcus pyogenes, Vibrio cholerae, Shigella dysenteriae, Listeria monocytogenes, Helicobacter pylori, and Salmonella typhi was observed with MIC values between 60 and 1000 µg/mL. The findings suggest that the synthesis of CuO NPs via green chemistry can serve as a potential substitute for traditional multi-step chemical synthetic routes.

Evaluation of antioxidant, catalytic and antidiabetic activity of Phaseolus vulgaris (French green bean) mediated nickel oxide and copper doped nickel oxide bimetallic nanoparticles

In this study, nickel oxide nanoparticles (NPs) and copper doped NiO bimetallic nanoparticles (Cu@NiO BMNPs) were synthesized using Phaseolus vulgaris extracts as reducing and stabilizing agents by sol gel methods. The chemical and physical properties of synthesized NiO NPs and Cu@NiO BMNPs were confirmed by various techniques, like UV Visible spectrophotometer (UV–Vis), Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Transmission Electron Microscope (TEM) and X-ray diffraction (XRD) analysis. The optical properties of both NPs observed by UV–Vis analysis with well-defined peak and band gap value 3.2 eV & 2.62 eV. FTIR analysis confirmed the presence of functional group of NPs with fruits extract. The morphology of NPs was confirmed by SEM and TEM analysis as polygonal, rod and spherical shape. The elements present in NPs were confirmed by EDX analysis. The crystalline size calculated based on the XRD analysis was 49.78 nm and 53.66 nm for NiO and Cu@ NiO NPs respectively which were found to be slightly smaller than particle size determined from SEM and TEM micrograph. Antioxidant activity of NPs was examined using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging radicals, Catalytic activities were screened by the degradation of Methylene blue (MB) and by the inhibition of alpha-amylase enzyme, antidiabetic activity of NPs were evaluated using acarbose as standard drug. The Cu@NiO BMNPs showed 77.60 % antioxidant, 76.98 % photocatalytic and 88.86 % antidiabetic activity, which were found to be more as compared to NiO NPs. The NiO and Cu@NiO BMNPs were synthesized for the first-time using P. vulgaris extracts. This study clearly showed that P. vulgaris extracts mediated mono- and bimetallic NPs were more stable and biocompatible than their respective bulk particles.

Influence of Treatment Time on the Synthesis of Copper Oxide Semiconductor Films by Cathode Cage Plasma Deposition

Influence of Treatment Time on the Synthesis of Copper Oxide Semiconductor Films by Cathode Cage Plasma Deposition

Cement modified and copper oxide enriched ferric sludge as oxygen carrier for chemical looping combustion

This study focuses on enhancing the performance of water treatment sludge as an oxygen carrier (OC) for chemical looping combustion (CLC) of municipal solid waste (MSW) syngas. High aluminate cement was introduced to augment the OC’s mechanical strength, concurrently preventing inter-particulate agglomeration, resulting in a commendable and low agglomeration rate of 3.44% after 50 cycles. The inclusion of CuO proves to be instrumental in boosting the OC’s reactivity, mitigating the loss of active components due to the addition of cement support. Notably, FSCuO10 (Ferric sludge with 10% CuO addition) demonstrates over 92% CO efficiency throughout 50 cycles, affirming the success of the dual modification of FS. The investigation also delves into comprehending the reduction process, agglomeration pathways, and the impact of varied CuO percentages has on OC performance. Extensive characterizations were conducted to elucidate OC transformations and their consequential effects on reactivity, physical characteristics, and overall performance. A noteworthy observation includes the outward migration of iron and copper during CLC, contributing to the stabilization of reactivity. In summary, the modifications implemented on FS, yield an improved OC for CLC purposes, maintaining its novelty and cost-effectiveness. The novelty stems from the interactions between CuO and FS, leading to improved reactivity and stability, as well as the extended CLC, which demonstrates the longevity of the OCs. This research contributes to the circularity of waste-derived products by effectively repurposing water treatment sludge and improving sustainable waste management practices.

Коррозионные характеристики композитов БрАМц9-2/06Х18Н9Т, полученных двухпроволочным электронно-лучевым аддитивным производством

Introduction. The development of novel materials based on copper alloys and stainless steel, as well as the determination of the optimal parameters for its processing make it possible to expand the area of its implementation, increase efficiency and service life of tools and constructions. The load-bearing parts of marine equipment (bearing constructions, piston cylinders, pumps, valves, gears, rotary instruments, etc.), made of austenitic steels or aluminum bronze, are in direct contact with sea water, so the problem of increasing its corrosion resistance in the presence of strong oxidizing agents (Cl-, F- anions) is relevant. One of the advanced and actively researched methods for producing copper/steel composites is additive manufacturing that allow fabricating complex parts through layer-by-layer growth. In particular, the synthesis of composites based on aluminum bronze and steel can be realized by wire-feed electron beam additive manufacturing. In order to implement composite materials produced via additive technologies in a humid (marine) climate, it is necessary to ensure not only high strength, but also corrosion properties. The purpose of this work is to study the corrosion resistance of composites, based on aluminum bronze CuAl9Mn2 and stainless steel ER 321 produced by dual-wire-feed electron beam additive manufacturing. Research methods. Examination of the surface of CuAl9Mn2/ER 321 composites before and after corrosion tests was carried out by methods of voltammetry and electrochemical impedance spectroscopy using a potentiostat-galvanostat. Results and discussion. Using a complex of electrochemical methods, it is revealed that the developed composites with a volume fraction of steel ≥ 25% demonstrate a significant decrease in anodic current densities and a simultaneous increase in charge transfer resistance. Composites with a steel content of 75 vol. % are characterized by the highest corrosion properties in 3.5 wt. % NaCl solution, which is referred to a reduction in corrosion rate by 9.5 times compared to aluminum bronze. It is shown that the main processes occurring on the surface of the composites (CuAl9Mn2 + ER 321) are anodic oxidation of copper and iron, leading to the formation of corrosion products – Cu2O and FeCl2.

Assessing the stability of binary copper oxide photocathodes and augmenting CuO water reduction performance: Comprehensive experimental and theoretical study

Using photocathodes such as Cu2O and CuO is an effective strategy for direct hydrogen production in photoelectrochemical (PEC) water splitting. The theoretical photocurrent densities of Cu2O and CuO are ∼14.7 and ∼35 mA cm−2, respectively, suggesting the superiority of CuO over Cu2O. However, the foremost drawback is the poor stability in aqueous solution under illumination. From this perspective, the PEC performance of CuO and Cu2O is compared via experimental and theoretical approaches. In this case, CuO outperformed Cu2O in terms of both PEC performance and stability, and the density functional theory (DFT) studies also evidently showed the same. Further, the AlOx and RuO2 were also loaded over CuO, and the CuO/AlOx/RuO2 delivered a photocurrent density of ∼2 mA cm−2 (@ +0.3 VRHE). The free energy plot shows the lower energy barrier of CuO/AlOx/RuO2 than CuO/AlOx and CuO, and it is present near and left side of the standard volcano plot, which further gives evidence for higher hydrogen evolution reaction (HER) performance.

Enhancement of antimicrobial properties and cytocompatibility through silver and magnesium doping strategies on copper oxide nanocomposites

In the present study, silver (Ag), magnesium (Mg), and the various molar ratios of Ag:Mg-doped copper oxide nanocomposites (CuO NCs) were synthesized by the co-precipitation method. The CuO NC samples calcined at 500 °C were further analyzed for their morphological, structural, functional, and optical properties. Adding single and dual doping increased the pristine CuO band gap from 1.28 to 1.50 eV. The Ag and Mg metal peaks were revealed in the Fourier transform infrared (FTIR) analysis, while an elevated Mg band was observed in all Mg-doped samples in the Raman results. All CuO NCs showed a monoclinic crystalline structure, flake, and rod-like morphologies. Microbes of Bacillus subtilis, Shigella dysenteriae, and Candida albicans were tested against different concentrations of CuO NCs. Better results for all tested microbes were observed with the 2 mg concentration. The high cytotoxicity effect was observed in the pristine and Cu:Ag (94:6) sample, and other CuO NCs, which demonstrated over 80 % viability in RAW 246.7 cells at a concentration of 0.5 µg/ml. Remarkably, over 94 % cell viability at 0.5 µg/ml was achieved with the Cu:Ag:Mg (94:3:3) NCs ratio, owing to the synergistic effect of the ion-releasing ability of Cu2+, Ag2+, and Mg2+ ions. It possesses a distinctive high aspect ratio shape, is ion-releasing, and has excellent cytocompatibility. The suitability of the Cu:Ag:Mg (94:3:3) NCs ratio for addressing microbial challenges in healthcare is suggested by their distinct characteristics, indicating the promising potential for future biomedical applications.

H2S gas sensing based on CuNi MOFs derivative with TiO2 quantum dot decoration applied for meat freshness detection

As food safety issues have been widely revealed and exposed, the pursuit of food for people has shifted from food and clothing to fresh and healthy. Currently, there are many detection systems for detecting meat freshness on the market. However, most of the problems still exist are that they cannot be monitored in real time, cannot guarantee traceless monitoring, and the cost is high. To solve these problems, this work has built a portable meat freshness detection system based on copper oxide (CuO)/nickel oxide (NiO) doped titanium oxide (TiO2) quantum dot composites and added real-time monitoring and remote monitoring and finally packaged it into an intelligent food box. Real-time monitoring of the freshness of meat can be carried out in a specific range regardless of the space. Hydrogen sulfide (H2S) has always been an essential indicator of meat decay. Therefore, in this paper, an H2S gas sensor based on CuO/NiO doped TiO2 quantum dot composites material is designed and fabricated, which can effectively and quickly identify H2S. The gas sensor exhibits excellent gas sensing characteristics for H2S with a detection limit of 100 parts per billion (ppb) and has excellent selectivity and repeatability, which because of the presence of p-p type heterojunctions in CuO/NiO. In addition, the feasibility of the system and material for analyzing the meat deterioration process is demonstrated through the test of different meat samples. It is firmly believed that this new type of sensor mentioned in this paper can make contribution to food quality monitoring.

Green synthesis of polyethylene glycol coated, ciprofloxacin loaded CuO nanoparticles and its antibacterial activity against Staphylococcus aureus

Antibacterial resistance requires an advanced strategy to increase the efficacy of current therapeutics in addition to the synthesis of new generations of antibiotics. In this study, copper oxide nanoparticles (CuO-NPs) were green synthesized using Moringa oleifera root extract. CuO-NPs fabricated into a form of aspartic acid-ciprofloxacin-polyethylene glycol coated copper oxide-nanotherapeutics (CIP-PEG-CuO) to improve the antibacterial activity of NPs and the efficacy of the drug with controlled cytotoxicity. These NPs were charachterized by Fourier transform infrared spectroscopy (FTIR), x-rays diffraction spectroscopy (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Antibacterial screening and bacterial chemotaxis investigations demonstrated that CIP-PEG-CuO NPs show enhanced antibacterial potential against Gram-positive and Gram-negative clinically isolated pathogenic bacterial strains as compared to CuO-NPs. In ex-vivo cytotoxicity CIP-PEG-CuO-nano-formulates revealed 88% viability of Baby Hamster Kidney 21 cell lines and 90% RBCs remained intact with nano-formulations during hemolysis assay. An in-vivo studies on animal models show that Staphylococcus aureus were eradicated by this newly developed formulate from the infected skin and showed wound-healing properties. By using specially designed nanoparticles that are engineered to precisely transport antimicrobial agents, these efficient nano-drug delivery systems can target localized infections, ensure targeted delivery, enhance efficacy through increased drug penetration through physical barriers, and reduce systemic side effects for more effective treatment.

Surface engineering of CuO-Cu2O heterojunction thin films for improved photoelectrochemical water splitting

The efficient production of green hydrogen poses a significant challenge that requires the development of active, low-cost, and stable catalysts. Copper oxide has emerged as a highly effective photocatalyst for water splitting, offering the advantages of being nontoxic, abundant, and inexpensive. Nonetheless, the photoelectrochemical water splitting (PEC) process can be enhanced through surface modification. In this study, we utilized single-source precursors for aerosol-assisted chemical vapor deposition (AACVD) in order to deposit thin films of copper oxide (CuO-Cu2O) heterojunctions onto a substrate composed of fluorine-doped tin oxide (FTO). The chosen precursor for this purpose was copper (II) nitrate hemi(pentahydrate). To further optimize the CuO-Cu2O films, a novel acid treatment involving the addition of varying quantities of acetic acid (AA) to the precursor solution was employed. Remarkably, this acid treatment resulted in a significant improvement in the photocurrent density of the CuO-Cu2O heterojunction. Notably, a 3 mL acid-treated CuO-Cu2O thin film exhibited an impressive photocurrent measure of −6.8 mA/cm2 at 0.0 V vs RHE in 0.5 M Na2SO4 electrolyte, compared to the performance of the untreated CuO-Cu2O thin film (−2.8 mA/cm2 at 0.0 V vs RHE). This catalyst demonstrated stability and a threefold increase in hydrogen production performance. The increase in photocurrent densities is closely linked to the influence of AA on two key factors: particle growth and structural defects, such as oxygen vacancies. This relationship has been confirmed through the examination of SEM, AFM, and PL spectra results. The findings of this study not only offer a novel approach to catalyst design but also propose a practical method for photoelectrochemical water splitting. This method holds great promise for achieving sustainable and renewable energy sources, as well as efficient green hydrogen production.

Effect of gamma and ultraviolet irradiation on the optical properties of copper oxide nanostructured thin films by chemical spray pyrolysis

Nanostructured copper oxide thin films were grown by the chemical spray pyrolysis (CSP) technique. Utilizing a homemade spray pyrolysis method, thin films are created. This work investigates the role of gamma ray and ultraviolet ray irradiation on the optical properties of copper oxide thin films(CuO) prepared. In this framework, used different substrate temperatures 300 °C, 350 °C, and 400 °C for the layers were grown on glass for the prepared CuO thin films. UV–visible spectrometer, field emission scanning electron microscopy (FE-SEM) and X-ray diffraction patterns(XRD) measurements were all used to characterize the samples. The UV–visible spectroscopy showed a decrease in the absorbance and the optical band gap of CuO thin films with the increase in the higher substrate temperatures before irradiation. Additionally, surface plasmon resonance peaks (λSPR) were observed at 329 nm. FE-SEM images revealed spherical-like shapes with an average diameter range of 48 nm,56 nm and 62 nm for 300 °C, 350 °C, and 400 °C, respectively. An analysis of X-rays revealed that CuO thin films contained the crystallographic planes of a monoclinic and an orthorhombic crystal system. Also, when samples were exposed to gamma and UVC radiation, the absorbance intensity of CuO thin films increased, but the optical band gap decreased.

The advanced copper oxide coating separator enhances the electrochemical performance of high-rate lithium-ion batteries

The performance and cycle life of Lithium-ion batteries (LIBs) are significantly influenced by the separator, a critical component. Traditional polyolefin separators can no longer meet the growing demand for energy storage. Coating conventional polyolefin separators with electrochemically inert ceramic materials can enhance stability but often increases weight and reduces battery capacity. This study introduces a novel separator coated with copper oxide (CuO), developed through a simple and efficient method. The CuO coating polypropylene (CuO@PP) separator demonstrates superior thermal resistance, enhanced electrolyte absorption, and increased porosity compared to conventional polypropylene (PP) separators. Additionally, the active participation of the CuO coating in electrochemical reactions during the charge-discharge process increases battery capacity. Results indicate that the CuO@PP separator provides an additional capacity of approximately 10 mAh g−1. The battery using the CuO@PP separator exhibited exceptional electrochemical properties in contrast to the traditional PP separator, with a first discharge capacity of 129.8 mAh g−1 at 10 C and a capacity retention rate of 92.4 % over 400 cycles at 10 C. Thus, enhancing the reliability and performance of LIBs by modifying the PP separator with a CuO coating presents a promising approach, offering novel perspectives for designing and manufacturing advanced battery separators.