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This work reports an effective laser synthesis of CuO nanoparticles, seeded in cellulose acetate butyrate (CAB). The structure and composition of the resulting nanocomposite were confirmed by scanning electron microscopy (SEM), X-ray diffraction (XRD), Uv–visible spectroscopy, Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), Raman spectroscopy and Fourier transform infrared spectrometry (FTIR). The characterization data showed that incorporating CuO into the CAB polymer matrix resulted in a heterogeneous organic–inorganic nanocomposite framework, such that suppressed crystallinity, decreased thermostability, and favorably reduced bandgap energy were seen in the CAB/CuO nanocomposite relative to the CAB material itself. The fabricated CAB/CuO nanocomposite was then successfully applied in the reduction of 2-nitrophenol (2-NP), a common organic pollutant in wastewater, where even low concentrations are harmful to human health and aquatic life. The reduction of the 2-nitrophenol compound was carefully monitored by UV–visible absorption spectroscopy. This revealed an apparent rate constant of 0.248 s−1 for the reduction process, demonstrating an excellent catalytic performance by the cellulose acetate butyrate film/CuO nanocomposite. In the technique reported, the reduction efficiency is a factor of time, with 100% efficiency achieved in 16 min. [ABSTRACT FROM AUTHOR]

Mixed oxy-compositions are lately used for water treatment that might be exploited as photo-catalyst, and adsorptive materials for the disposal of water pollutants. Cupric oxide (CuO), lanthanum oxide (La2O3), and graphene oxide (GO)-based nanocomposites show an interest in water treatment applications owing to the adsorptive feature of carbon-based nanoparticles (NPs), besides low band gap of metal oxides that boosts photo-catalytic process. CuO/La2O3/GO-based nanocomposites are prepared and tested for their thermal stability, and dye removal activity. The change in nanocomposites structure upon the incorporation of CuO and La2O3 into GO nanosheets is inspected via TEM micrographs showing a decline in lanthana rod length to be 200 nm on average. Additionally, the improved roughness structure and the compact grain size appear in SEM micrographs reports CuO grain size reduction reaching an average size of 250 nm. The roughness parameters of CuO/La2O3/GO are extraordinarily heightened in which the supreme value of roughness average is 7.6 nm. Ternary nanocomposite exhibits a maximum value (85%) as a methylene blue (MB) dye removal. Based on these obtained results, the fabricated nanocomposites are recommended for water treatment due to their enriched physicochemical and morphological features as well as the better thermal stability and exerted dye removal activity.

Cu-oxide nanophases (CuO, Cu2O, Cu0) constitute highly potent nanoplatforms for the development of efficient Artificial Photosynthesis catalysts. The highly reducing conduction band edge of the d-electrons in Cu2O dictates its efficiency towards CO2 reduction under sunlight excitation. In the present review, we discuss aspects interlinking the stability under photocorrosion of the (CuO/Cu2O/Cu0) nanophase equilibria, and performance in H2-production/CO2-reduction. Converging literature evidence shows that, because of photocorrosion, single-phase Cu-oxides would not be favorable to be used as a standalone cathodic catalyst/electrode; however, their heterojunctions and the coupling with proper partner materials is an encouraging approach. Distinction between the role of various factors is required to protect the material from photocorrosion, e.g., use of hole scavengers/electron acceptors, band-gap engineering, nano-facet engineering, and selectivity of CO2-reduction pathways, to name a few possible solutions. In this context, herein we discuss examples and synthesis efforts that aim to clarify the role of interfaces, faces, and phase stability under photocatalytic conditions.

The CuO-nanoleaf/g-Al2O3 catalyst was synthesized through wet chemical impregnation and had promising catalytic activity in reducing p-Nitrophenol (PNP) into p-Aminophenol (PAP). The synthesis was conducted in situ with Ethylene Glycol as a stabilizer agent of the CuO-nanoleaf structure and g-Al2O3 as catalyst support with high adsorption ability. Furthermore, the crystal phase, morphology, element composition, and specific surface area were investigated by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and N2 adsorption-desorption, respectively. The XRD pattern showed the crystal phase of CuO and g-Al2O3 in the composite, and the morphology was successfully reported using FESEM. The increase in the specific surface area of the catalyst indicates that the CuO material was well composited in g-Al2O3. The catalyst has good activity in reducing PNP to PAP with 93.53% PNP conversion within 4 min. In addition, the reduction reaction of PNP with excess NaBH4 could be categorized as pseudo-first order kinetic with a constant rate of 0.6935 min−1 for CuO-nanoleaf/g-Al2O3 catalyst. The loading catalyst and temperature reaction effect on PNP conversion were also investigated. The results showed that 94.18% PNP conversion was obtained within only 2.5 min under the optimized conditions. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

In this study, it was aimed to determine some physiological effects of CuO nanoparticle on C. demersum. The plants were collected from an uncontaminated pond in Gaziantep province. Different concentrations of CuO (0, 25, 50, 100 and 200 mg/L) were applied to the macrophytes after being acclimatized in controlled conditions. Some analyses were made on macrophytes harvested at the end of the application. The contents of protein, total carbohydrate, photosynthetic pigment, total phenolic compound, non-protein sulfhydryl groups of tissues increased with increasing CuO concentration under the influence of applied CuO concentrations. In addition, increases in hydrogen peroxide and MDA contents were also detected. As a result, it was determined that the applied CuO concentrations caused some physiological changes in C. demersum tissues.

Research on combined phytotoxicity of perfluorooctanoic acid (PFOA) and nanoparticles is very important for the remediation of PFOA contaminated soil and further assessment for the potential of nano-enhanced phytoremediation. Here, joint effects of PFOA and CuO nanoparticles (nCuO) in plants were studied by exposing radish (Raphanus sativus L.) to PFOA (4 mg/kg) and nCuO (200 and 400 mg/kg) for 30 days, and measuring for contaminant accumulation, radish biomass, photosynthesis profiles and nutrient contents. Results showed that PFOA accumulated highly in radish organs but showed limited effects on radish biomass. nCuO could increase the transfer rate of PFOA from root to shoot and reduce PFOA accumulation in edible root part, but higher nCuO lead to decreased radish biomass. Reversely, PFOA alleviated the adverse effects of nCuO on leaf photosynthesis and root metabolism of vitamins and amino acids. These results provided basics for exploring possibility of nano-enhanced phytoremediation for PFOA soil pollution.

The current work is aimed to fabricate a set of hybrid nanocomposite membranes containing cellulose acetate (CA) reinforced by pure zinc oxide or mixed metal oxides in the form of CuO(0.01, 0.05, 0.1)/ZnO for biological Interest. Pure ZnO and CuO(0.01, 0.05, 0.1)/ZnO mixed oxides have been also prepared using eco-friendly, non-toxic, and low coast methods. CA@ZnO nanocomposite and CA@CuO(0.01, 0.05, 0.1)/ZnO hybrid nanocomposite membranes have been synthesized by a simple, straightforward, non-toxic, and environmentally acceptable casting approach. The chemical structure for the fabricated materials has been confirmed by common characterisation tools including: XRD, SEM, HRTEM, TGA thermal analysis. The average size of the prepared nanoparticle was 25.40 and 10.3 nm for ZnO and CuO/ZnO, respectively. The order of higher thermal stability for the fabricated materials are: CA@CuO(0.01)/ZnO

Free radical scavenging property of different ligand directed nanostructures of CuO (rod‐, sphere, flower‐, and star‐shaped) prepared through aqueous based chemical precipitation route using various carboxylic acids (viz. tartaric acid, citric acid and acetic acid) have been investigated using N,S co‐doped carbon dots (NSCDs) as a novel fluorescent probe which is validated through diphenyl‐1‐picrylhydrazyl (DPPH) free radical scavenging assay and EPR study. The rod shaped nanostructures having the highest negative surface potential and lowest BET surface area compared to other morphologies, were found to show the highest radical scavenging ability which was corroborated with the maximum decrease of the DPPH absorption peak in UV‐vis spectra, largest attenuation of the DPPH free radical signal in EPR intensity and the maximum quenching of the fluorescent intensity of the NSCDs probe. [ABSTRACT FROM AUTHOR]

Increasing global demand for energy is inevitable. As energy dependence increases, more stable and efficient forms of energy are needed. Solar energy is the only viable renewable energy source that can meet this growing global demand. But low conversion efficiency is the major challenge for the solar cell devices. Therefore, to achieve better efficiency, CuO is introduced first time as a tunnel oxide passivated layer in this research work. Incorporation of CuO as a tunnel oxide layer between the substrate and base is the unique feature of this proposed work. The CuO tunnel oxide layer acts as an interface passivation layer and restrict the recombination of electrons and holes near the back contact. As a result, the recombination at the contact reduces which ultimately increases the minority charge carrier's lifetimes in the solar cell, and hence enhances the open circuit voltage (Voc) from 0.71 to 0.76 V and the efficiency from 21.98 to 23.84% of the solar cell. [ABSTRACT FROM AUTHOR]

In this article, the estimation of CuO-liquid paraffin nanofluid viscosity was assessed using response surface method (RSM) and artificial neural network (ANN) methods. Since CuO-liquid paraffin nanofluid is Newtonian, two parameters of temperature and mass fraction were introduced in ANN and RSM techniques at 25–100 ° C , 0.25–6 wt.%. Both methods map the three-dimensional input space to one-dimensional space (viscosity). A response surface cubic model was approved by applying ANOVA and calculations showed an R2 value of 0.923 and a maximum margin of deviation of 10.482%. Efforts revealed that ANN with five neurons takes precedence over others. The R2 and maximum deviation margin were 0.994, and 3.266%, respectively. Finally, the comaprison of ANN and RSM methods indicated that the ANN method is more accurate than the RSM for conducting the nanofluid viscosity. The accuracy of ANN was such that for 50% of points, MOD was less than 1%. For MOD in the range of 0–2%, 90% of points can be predicted with an error of less than 2%. This figure for RSM was only 37%. [ABSTRACT FROM AUTHOR]

Cu2O is among the most promising photocatalysts for CO2 reduction, however its photocorrosion remains a standalone challenge. Herein, we present an in situ study of the release of Cu ions from Cu2O nanocatalysts under photocatalytic conditions in the presence of HCO3 as a catalytic substrate in H2O. The Cu-oxide nanomaterials were produced by Flame Spray Pyrolysis (FSP) technology. Using Electron Paramagnetic Resonance (EPR) spectroscopy in tandem with analytical Anodic Stripping Voltammetry (ASV), we monitored in situ the Cu2+ atom release from the Cu2O nanoparticles in comparison with CuO nanoparticles under photocatalytic conditions. Our quantitative, kinetic data show that light has detrimental effect on the photocorrosion of Cu2O and ensuing Cu2+ ion release in the H2O solution, up to 15.7% of its mass. EPR reveals that HCO3 acts as a ligand of the Cu2+ ions, promoting the liberation of {HCO3-Cu} complexes in solution from Cu2O, up to 27% of its mass. HCO3 alone exerted a marginal effect. XRD data show that under prolonged irradiation, part of Cu2+ ions can reprecipitate on the Cu2O surface, creating a passivating CuO layer that stabilizes the Cu2O from further photocorrosion. Including isopropanol as a hole scavenger has a drastic effect on the photocorrosion of Cu2O nanoparticles and suppresses the release of Cu2+ ions to the solution. Methodwise, the present data exemplify that EPR and ASV can be useful tools to help quantitatively understand the solid–solution interface photocorrosion phenomena for Cu2O. [ABSTRACT FROM AUTHOR]

A flexible and portable triboelectric nanogenerator (TENG) based on electrospun polyvinylidene fluoride (PVDF) doped with copper oxide (CuO) nanoparticles (NPs, 2, 4, 6, 8, and 10 wt.-% w.r.t. PVDF content) was fabricated. The structural and crystalline properties of the as-prepared PVDF-CuO composite membranes were characterized using SEM, FTIR, and XRD. To fabricate the TENG device, the PVDF-CuO was considered a tribo-negative film and the polyurethane (PU) a counter-positive film. The output voltage of the TENG was analyzed using a custom-made dynamic pressure setup, under a constant load of 1.0 kgf and 1.0 Hz frequency. The neat PVDF/PU showed only 1.7 V, which further increased up to 7.5 V when increasing the CuO contents from 2 to 8 wt.-%. A decrease in output voltage to 3.9 V was observed for 10 wt.-% CuO. Based on the above results, further measurements were carried out using the optimal sample (8 wt.-% CuO). Its output voltage performance was evaluated as a function of varying load (1 to 3 kgf) and frequency (0.1 to 1.0 Hz) conditions. Finally, the optimized device was demonstrated in real-time wearable sensor applications, such as human motion and health-monitoring applications (respiration and heart rate). [ABSTRACT FROM AUTHOR]

An aqueous extract of the shade-dried parts of Asparagus aethiopicus L. and Asparagus densiflorus (Kunth) Jessop was used to synthesize copper (CuO) nanoparticles (Cu NPs). UV-visible spectroscopy was performed to assess the formation of Cu NPs. Maximum absorbance was obtained between 310–360 nm, confirming the formation of Cu NPs. CuO NPs were effective against Pseudomonas aeruginosa (ATCC 27853), a gram-negative human pathogenic bacterium. The bacterial growth curve showed that the NPs inhibited bacterial growth. This study was conducted using different parts of the plant, such as the roots, shoots, fruits, and seeds of A. aethiopicus and the roots and shoots of A. densiflorus. The fruit and seeds of A. aethiopicus showed better results than the roots and shoots. Therefore, employing green synthetic processes inhibits the release of harmful by-products. Compared to traditional techniques of NP synthesis, the transition to the extracellular production of CuO NPs utilizing dried biomass appears to be economical and environmentally beneficial. [ABSTRACT FROM AUTHOR]

Although significant advances have been witnessed in the application of nanozymes in recent years, exploring new strategies to enhance the enzyme-like activity of nanozymes is of urgent importance. Herein, we investigate the feasibility of accelerating the peroxidase-like reaction rate of CuO nanostructures through Fe doping. The coprecipitation method was used to synthesize Fe-doped CuO (Fe-CuO) nanozymes, and the results indicate that the diversified valence of Fe benefits the redox reaction driven by CuO-based nanozymes. With the improved peroxidase-like activity, the Fe-CuO nanozyme enables the significant chromogenic oxidation reaction of 3,3′,5,5′-tetramethylbenzidine (TMB), facilitating the construction of a visual sensing platform for the sensitive and selective determination of ascorbic acid. Under optimal conditions, the absorbance at 652 nm decreases linearly with the concentration of ascorbic acid in the range of 5–50 μM, with a limit of detection as low as 4.66 μM. This work exemplifies the activity enhancement for peroxidase-mimicking nanozymes with a metal-doping strategy and provides a broad prospect for the design of more high-performance nanozymes for biosensing applications. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the formation of Cu2O thin films on fluorine-doped tin oxide glass substrate by electrochemical deposition. The obtained Cu2O thin films were annealed in air at various temperatures from 300 to 500°C. X-ray diffraction analysis shows that as-deposited and annealed thin films at 300°C have a cubic structure with a Cu2O composition. The Cu2O films annealed at 400 and 500°C were completely converted onto the monoclinic structure with CuO composition. On the other hand, atomic force microscope and scanning electron microscope images showed that the shape of Cu2O grains was changed significantly from cubic to grains upon annealing. Mott–Schottky and photoelectrochemical measurements indicate that Cu2O thin films exhibit p-type conductivity before and after annealing. Photoluminescence measurements indicated two peaks at around 523 and 355 nm, which confirmed the existence of Cu2O and CuO thin films, respectively. Finally, the CuO nanostructures obtained at 500°C exhibited a high photocurrent enhancement and stability compared to as-deposited sample. As a consequence, the optical bandgap was reduced from 2.41 to 1.75 eV. [ABSTRACT FROM AUTHOR]

Our work consists in depositing the copper oxide Fe doped CuO films by spray obtained from the solution of copper chloride CuCl2 and FeCl2 with a percentage of 2, 4; 6 and 8%, on glass substrates at a temperature of 3500c. The thin films obtained are characterized by X-ray diffraction, visible UV spectroscopy and the four-point technique. With X-ray diffraction, high peak intensity is obtained for the preferential orientations of (002) and (111), this intensity increases as the doping rate increases and gives us a more crystalline structure for a doping rate of 8%, also a grain size were estimated. The transmission of our films varies between 55% and 75% with a high absorption in the visible domain, the resistivity of our films increase with the increase of doping rate and the gap energy varies between 4.00 and 1.47 eV. [ABSTRACT FROM AUTHOR]

In the present study, we have investigated the impact of the molar concentration of the precursor solution on structural and optical properties of CuO thin films, deposited by air-pressurized spray pyrolysis technique. A set of CuO thin films samples were prepared with various molar concentrations ranging from 0.01 to 0.2 M at a substrate temperature of 300 °C. The film's structure and morphology were characterized by means of X-ray diffraction and scanning electron microscope. The film's optical properties were studied using photoluminescence spectrophotometer (PL) and UV–visible spectroscopy. The obtained results indicate that molar concentration of the precursor solution is a key parameter for controlling the growth mechanism additional to the structural, optical and morphological properties of CuO thin films. An increase in molar concentration leads to an increment in the deposition rate and a reduction in the disorder of the films. [ABSTRACT FROM AUTHOR]

Analysis of the optical properties of a gradient (Ti,Cu)Ox thin film is presented in this paper. The thin film was prepared using reactive co-sputtering of Ti and Cu targets. The desired elemental concentration profiles of Cu and Ti versus the thin film thickness were obtained by changing the power delivered to the magnetron equipped with Cu, while the powering of the magnetron equipped with the Ti target was maintained at a constant level during the film deposition. Optical properties were analysed using the reverse engineering method, based on simultaneously measured optical transmittance and reflectance. Detailed microstructure analysis performed using transmission electron microscopy investigations revealed that the thin film consisted of at least four areas with different structural properties. Finding a satisfying fit of theoretical to experimental data required taking into account the heterogeneity in the material composition and microstructure in relation to the depth in the prepared gradient thin film. On the basis of the built equivalent layer stack model, the composition profile and porosity at the cross-section of the prepared gradient film were evaluated, which agreed well with the obtained elemental and microscopy studies. [ABSTRACT FROM AUTHOR]

The composite of CuO coated MIL‐101(Fe) (CuO@MIL‐101(Fe)) was successfully prepared using a one‐pot hydrothermal technology. X‐ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Brunauer–Emmett–Teller (BET), and TG technologies were used to characterize its structural, morphological, and physicochemical properties. CuO@MIL‐101(Fe) exhibited a better pH adaptivity, a faster removal ratio of 95.8% for glyphosate within 10 min at pH 7, and a higher selectivity of adsorption capacity, even reaching 231.6 and 233.5 mg g−1 with coexisting Cl− (10 mmol L−1) and SO42− (10 mmol L−1). The enhanced adsorption performances of CuO@MIL‐101(Fe) may be caused by Cu forming a coordination interaction with glyphosate. A possible mechanism of glyphosate removal was discussed on the basis of the FTIR and X‐ray photoelectron spectroscopy (XPS) analysis. CuO@MIL‐101(Fe) composite would be more favourable to capture glyphosate from wastewater. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) Ti3C2Tx Mxene has currently demonstrated significant potential for gas sensing application with a high signal-to-noise ratio at room temperature. Herein, we present the mixture of popular NH3 sensing materials such as graphene oxide (GO), copper oxide (CuO), and zinc oxide (ZnO) into Ti3C2Tx Mxene to be a high-performance NH3 gas sensor at room temperature. Various nanocomposites such as Mxene/GO, Mxene/ZnO, Mxene/CuO, Mxene/GO/ZnO, Mxene/GO/CuO, Mxene/ZnO/CuO, and Mxene/GO/ZnO/CuO were synthesized via the hydrothermal method and used as NH3 sensing materials in room-temperature gas sensors. The Ti3C2Tx MXene/GO/CuO/ZnO nanocomposite gas sensor exhibited the best NH3 gas sensor. The effects on the weight ratios of Ti3C2Tx MXene/GO/CuO/ZnO were also investigated, and the optimal Ti3C2Tx MXene/GO/CuO/ZnO weight ratio was determined to be 9:1:5:5. The optimal Ti3C2Tx MXene/GO/CuO/ZnO based gas sensor showed a high response of 96% at 200 ppm of NH3, humidity independence in the range of 30–70%RH, good linear relationship (R2 = 0.998), low limit of detection of 4.1 ppm, and high selectivity to NH3 over several gases/VOCs including formaldehyde, ethanol, methanol, isopropanol, toluene, and acetone. The NH3-sensing mechanism was proposed based on the modulation of complex p–n heterojunctions via the electron accumulation layer in the n-type of GO/CuO/ZnO and the electron depletion layer in the p-type Ti3C2Tx Mxene. [ABSTRACT FROM AUTHOR]

The p-n junction is the principal mode of optoelectronic semiconductor material. At present, we submit a solution-based attempt at the synthesis of nanostructured p-type CuO and n-type ZnO nanocomposite (NC) heterostructure films. Bare and Cobalt (Co)-doped CuO–ZnO NC films have been produced on glass slides using the SILAR (Successive Ionic Layer Adsorption and Reaction) method. The influence of Co-doping concentration on the physical characteristics of CuO–ZnO NC heterostructure films was investigated. XRD spectrums indicated the phase and structural purity of solution-based synthesized CuO–ZnO NC samples. The surface topographical, as well as optical and electrical properties of heterostructure films were, also investigated. While the bare CuO–ZnO NC film has a ∼38% transmission near 1000 nm wavelength region, the 2.0% Co-doped CuO–ZnO NC film has ∼31% of optical transmission. The sheet resistance value of the grown 2.0% Co:CuO–ZnO NC sample is almost 13 times lower than that of the bare CuO–ZnO NC sample at 400 K temperature. As a consequence, our attempt ensures a novel strategy for the production and performance optimization of CuO–ZnO NC heterostructures in the implementation of optoelectronics. [ABSTRACT FROM AUTHOR]

The effect of ageing on electrical properties of Fe-doped CuO thin films was investigated in this study. The pure and Fe (2, 4, 6; mol%)-doped CuO films were prepared by using spin coating technique and characterized by using X-ray diffractometer (XRD), field emission-scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), UV–Vis spectrophotometer and two-probe technique. The results showed that the pure and Fe-doped CuO thin films had a monoclinic phase and the monoclinic structure did not change with Fe doping. As the crystal size increased, the dislocation density and strain decreased. From the electron microscopy images, it is clearly observed that the pure and Fe-doped CuO thin films contain spherical structures. The energy band gaps of the thin films were estimated as 3.80, 3.89, 3.98 and 4.11 eV, respectively. The conductivity of the thin films increased with increasing temperature from 300 to 450 K. The activation energy of the films increased with Fe doping. These thin films are potential candidates for solar cell applications. [ABSTRACT FROM AUTHOR]

The effect of the energy, the interval between the pulses, and the number of double laser pulses on the formation of the component and charge composition of laser plasma by laser spark spectrometry (LSS-1 spectrometer) was studied. The processes leading to the formation of mixed nanopowders of copper and aluminum oxides, precursors for the production of nanoceramics and films of CuAlO2 copper aluminates by the action of double laser pulses on a hybrid target consisting of cemented aluminum and copper plates, from AD1 and M2 alloys were investigated. It was shown that precursors for the manufacture of nanoceramics and nanofilms of CuAlO2 copper aluminates can be obtained by the successive action of a series of double laser pulses with energy of 53 mJ and an interval of 10 μs on a hybrid target. A closed glass weighing bottle containing the target was used for the products formed during interaction of the aluminum and copper ions with atmospheric oxygen. The size of the initial particles, determined by means of a high-resolution electron microscope, amounted to 30–45 nm. The particles were assembled into agglomerates and had a crystalline structure and spherical form. On account of the purely diffusion transfer mechanism of the fractals the size and amount of the fractal aggregates settling on the support situated at the bottom of the cuvette were several times greater than the amount of the products that settle on the side support. The main contribution to change in the intensity of the spectral lines for the Al and Cu atoms and ions and the AlO molecular bands comes from interaction of the second pulse with the condensation products formed in the channel after the action of the first pulse. With increase in the number of long-lived fractal aggregates in the air the intensity of molecular bands and lines decreases by ~1.5 times for Al III and by ~2 times for copper, which is due to active interaction of the long-lived large fractals that accumulate in the air with the incident radiation. [ABSTRACT FROM AUTHOR]

The issue of industrial dyes has risen to the forefront of environmental concerns, as they are now recognized as a prevalent form of industrial waste that pollutes our surroundings. As such, it is imperative that efforts be made to address their toxicity, with a view to safeguarding the environment and public health. To this end, the application of nanotechnologies presents a promising solution to the challenge of mitigating the harmful effects of industrial dyes on our environment. Copper oxide nanoparticles (CuO NPs) have been found to possess strong photocatalytic properties and are effective in degrading toxic dyes in polluted water and industrial effluents. In this experimental work, CuO NPs were synthesized using Citrus limon leaves extract as source of bioactive molecules to obtain stable NPs. Microscopic and spectroscopic analyses confirmed the formation of CuO NPs with size range of 20–25 nm with spherical shape. In addition, the prepared NPs utilized as photocatalyst against Remazol Brilliant Blue R (RBBR) dye, which shows remarkable potency within 180 min with degradation efficiency ∼90%. Thus, CuO NPs can be used as sustainable, cost-effective and efficient alternative for the removal of toxic industrial effluents from water bodies. [ABSTRACT FROM AUTHOR]

Cathode in photocatalytic fuel cell (PFC) plays a crucial role in degradation of organic contaminants. In this study, synthesized copper oxide (CuO) was loaded on carbon plate and used as photocathode in PFC for degradation of synthetic azo dye Reactive Black 5 (RB5) and real textile wastewater. Morphology and structural phase of the synthesized CuO were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Several operating parameters had been investigated such as light irradiation, initial dye concentration, and pH of azo dye solution within 6 h of irradiation time. The lowest initial concentration of RB5 (10 mg L−1) achieved 100% color removal compared to the highest initial concentration (40 mg L−1) which only achieved 77.1% color removal within 6 h of irradiation time. The influence of external resistance was significant in electricity generation but trivial in dye degradation efficiency. The external resistance of 6000 Ω yielded highest maximum power density, with Pmax of 0.2631 μW cm−2, followed by 1000 Ω (0.2196 μW cm−2) and 8000 Ω (0.1587 μW cm−2), respectively. The real textile wastewater with dilution ratio (DR) 1:6 yielded the highest energy conversion efficiency, η (3.62%), followed by DR 1:4 (3.19%) and DR 1:2 (1.96%), respectively. [ABSTRACT FROM AUTHOR]

An integration of S-scheme heterojunction catalyst with surface plasmon resonance effect is the prime focus of current research activites in the field of visible light driven photocatalytic hydrogen (H 2) evolution. Herein, a sol-gel route is used to design a heterojunction of ZnO–CuO–Au. The effect of process parameters, including irradiation time, catalyst dose, and sacrificial reagents on the hydrogen evolution is studied. The S-scheme ZnO–CuO–Au heterojunction catalyst demonstrated high surface area, better optical absorption response in the visible part of light spectrum, and improved separation and transportion of charge carriers as verified by DRS, PL, and photoelectrochemical studies. The maximum H 2 evolution rateof ZnO–CuO–Au reaches 4655 μmolh−1g−1, which is 5 and 3.2 times higher than ZnO–CuO and Au–ZnO catalysts, respectively. A possible reason of this increase in H 2 evolution rate is inhibited recombination of charge carriers because of the S-scheme design to increase electrons with strong reduction potential and prolong lifetime, Au serves as an SPR source and conductive channel to swift the transfer of electrons and high density of active sites. This work offers innovative insight into designing plasmonic metals-modified S-scheme systems for solar fuel production. • ZnO–Au–CuO S-scheme heterojunction is synthesized via sol-gel. • Au NPs increased the light absorption due to LSPR effect. • Influence of catalyst dose, irradiation time and sacrificial agent is discussed. • Built-in electric field promoted charge transfer results in efficient H 2 evolution. [ABSTRACT FROM AUTHOR]

Influence of CuO on the linear/nonlinear optical, elastic, physical features, and radiation protection performance of CuO-based glasses in form (50-y/2)Na2O + (50-y/2)P2O5 + yCuO, (y = 0.0–40 mol%) has been studied in the current article. The density was increased from 2.47 to 3.26 g.cm−3 accomplished with a concurrent decrease in the oxygen molar volume from 13.76 to 12.97 cm3.mol−1 as the mol% of [Cu2+] enhanced in the tested glasses. Also, the Vickers hardness (Hv) was found to increase with increasing CuO content in the current glass systems. The notable tendency of mass attenuation coefficient (MAC) values in the investigated energetic photon range obeyed the sequential order: MACCuI-0 < MACCuI-10 < MACCuI-20 < MACCuI-25 < MACCuI-30 < MACCuI-33 < MACCuI-40. Also, we found that the linear attenuation coefficient (LAC) increased, while the half-value-layer (HVL), and transmission coefficient (TF%) also decreased. The HVL values of the current samples were compared with standard glasses, and it was found to those CuO-based samples possessed a comparable photon protection capacity as RS-360 and RS-520. The linear (nlinear) and nonlinear ( n 2 optical ) refractive index increased from 3.914 to 3.983 and from 2.76 × 10–9 and 3.15 × 10–9. Results uncovered that the optical, radiation protection efficiency and elasto-mechanical characteristics might at the same time be adjusted for an in- or/and out-door scientific and medical applications. [ABSTRACT FROM AUTHOR]

Copper oxide (CuO) as the photocatalyst nanoparticle was prepared by the solution combustion technique. During the synthesis, iron atom source, which was iron nitrate, was added to the reaction medium to obtain iron doped CuO nanoparticles. In addition, the iron doped CuO nanoparticles were combined with the conducting polymer, which was polyaniline, through the in-situ polymerization technique. The chemical and crystal structure, optical property and the photocatalytic activity of the CuO nanoparticles and their composites were studied as a function the dopant atom concentration of CuO and the photocatalyst composition of the composites. The prepared samples were characterized by Fourier-transform infrared spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, fluorescence spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray (EDX) spectroscopy and UV-Vis absorption spectroscopy. The photocatalytic activity of the prepared samples was evaluated by the photocatalytic degradation of a model dye, methylene blue, under visible light irradiation. In addition, the Cr(VI) photoreduction efficiency of the prepared samples were studied. Iron atoms might enter into the substitutional sites of CuO. The iron atoms might act as a trapping center to capture the photoinduced charge carriers of CuO, promoting both the charge separation and the photocatalytic activities. The photocatalytic dye degradation efficiency and the Cr(VI) photoreduction efficiency of the iron doped CuO increased by almost 17% compared to undoped CuO. The composites with low polyaniline content might promote the charge separation because of the difference between the band potentials of CuO and polyaniline as shown in the graphical abstract. The composite with 80 wt.% of the iron doped CuO exhibited the highest photocatalytic dye degradation of almost 72% and the Cr(VI) photoreduction efficiency of almost 56%. Proposed photocatalytic dye degradation and Cr(VI) photoreduction mechanism of CuO-Fe3/Pani Highlights: Doping CuO with iron atom and coupling CuO with polyaniline enlarged the optical band gap energy and enhanced both the photocatalytic dye degradation efficiency and the Cr(VI) removal efficiency. Doped CuO and CuO/Polyaniline composites provided low recombination rate of the photogenerated charge carriers. Superoxide radicals dominated the photocatalytic dye degradation reaction. The potential for use of CuO as a photocatalyst has been increased by doping with iron atom and compounding with polyaniline. [ABSTRACT FROM AUTHOR]

Abstract In this research, thin film composite structures were used to prepare optoelectronic devices from bare and Bi‐substituted p‐CuO/n‐ZnO systems. The p‐CuO/n‐ZnO composite thin film structures were prepared by the SILAR technique, and the influences of two different Bi contents on the structure and main physical performances of the samples were investigated. The X‐ray diffraction (XRD) technique showed that the composited thin film materials were multiphased in rutile hexagonal (wurtzite) phase (ZnO) and monoclinic tenorite phase (CuO) type crystal structure. The obtained surface morphological results presented that the structure exhibits an almost homogeneous, plate‐like surface distribution, and depending on the increase of Bi concentration, the plate‐like sheet area widens from ~2.5 μm to 10 μm and the layer boundaries decrease. FT‐IR and Raman spectroscopy were used to investigate the various vibration and Raman active phonon modes of Bi:p‐CuO/n‐ZnO nanostructured heterostructures. For a comprehensive analysis of the optical bandgap of the fabricated composite samples, the estimated values were obtained from the Tauc plot. Produced samples exhibited an Ohmic behavior and dc resistivity values of films can be determined via Ohm′s Law. The adjusted sheet resistance value of 11.51 MΩ/sq when the content of Bi 3.0 % in the growth bath.

We evaluated an absorbance effectiveness on the solar spectrum using an absorption figure of merit (a-FOM) for the conducting thin films. In particular, Ni-doped and un-doped CuO thin films were deposited by a facile and sustainable solution-processed synthesis, whose Ni doping concentration was varied to be 0.2, 0.6, 1, 2, 3, 4 wt%. We observed a change of smooth surface to an appearance of nanoparticles by Ni doping, which supported to form of a plasmonic mechanism for improving the light capture and retention. The absorption of long wavelengths was improved and extended to the near-infrared range. That is, the bandgap energy decreased from 2.10 to 1.88 eV with Ni doping. Also, we found that the absorption length decreased from 99.93 nm to 63.80 nm as the Ni doping increased. In addition, the CuO-based film with 4 wt% Ni doping showed a maximal value of a-FOM as high as 30.88 Ω−1cm−1, corresponding to a resistance of 2.07 MΩ/sq and an absorption length of 63.80 nm. Our finding suggested that Ni-doped CuO thin films can be considered as an excellent selection of absorbent conductive oxide layers for application in optoelectronic devices and solar cell systems.

Nanotechnology focuses on materials at the molecular and atomic levels, with sizes ranging from 0.1 to 100 nm. This study explores the synthesis and characterization of copper oxide (CuO), nickel oxide (NiO), and hybrid nanoparticles using an aqueous seed extract from Myristica fragrans . The nanomaterials underwent comprehensive characterization employing various techniques: UV analysis, FTIR spectroscopy, XRD, TGA, EDX and SEM. We explored their biological applications through antioxidant and antibacterial assays. UV analysis determined the optical absorption spectra values for CuO, NiO and hybrid nanoparticles. FTIR analysis confirmed functional groups in the plant extract responsible for capping and reducing the reaction medium. XRD and SEM analysis demonstrated the crystalline nature and morphology of the nanoparticles. CuO nanoparticles exhibited polyhedral morphology, while NiO nanoparticles were primarily spherical with some agglomeration. The CuO-NiO hybrid nanoparticles showed a wurtzite morphology with significant agglomeration and larger mean size than CuO and NiO nanoparticles. EDX indicated higher quantities of Cu and Ni. XRD spectra revealed the average particle sizes of nanoparticles. TGA indicated the thermal stability of the nanoparticles, with hybrid nanoparticles being the most stable. The nanoparticles exhibited excellent antioxidant activity, with hybrid nanoparticles showing the highest values in measuring total antioxidant capacity, total reducing power (TRP), ABTS assay, and DPPH-free radical scavenging assay at 400 μ g/mg. Antibacterial assays against multidrug-resistant bacterial strains demonstrated that antibiotics-coated hybrid nanoparticles exhibited potent antibacterial properties against Staphylococcus aureus , Escherichia coli , and Pseudomonas aeruginosa . In conclusion, CuO, NiO, and CuO-NiO hybrid nanoparticles mediated by Myristica fragrans showcase promising characteristics for various applications, especially in biomedical and clinical settings. The nanoparticles eco-friendly synthesis and biocompatible nature make them attractive candidates for future research and development.

Introduction . Owing to the increasing use of organic dyes, the biosynthesis of metal oxide nanocatalysts is urgently needed as an economical and environmentally friendly solution to reduce their waste release. Method . In this study, we synthesized copper oxide nanoparticles (CuO NPs) by the sol–gel method using Croton macrostachyus leaf extracts as capping and reducing agents. The biosynthesized CuO catalysts were characterized using x-ray diffraction analysis (XRD), thermogravimetric differential thermal analysis (TGA-DTA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR). Result . The result showed that the synthesized CuO NPs had a crystallite size of about 9 nm and had good crystalline texture. Furthermore, the catalyst showed the best catalytic reduction performance in 1 min for methylene blue (MB) and 3 min for methyl orange (MO). Furthermore, the CuO catalyst synthesized using Croton macrostachyus leaf extract resulted in apparent rate constant (K _app ) values for MB and MO of 0.06793 s ^−1 and 0.01877 s ^−1 , respectively. Discussion . The recyclability of the CuO catalyst was investigated, and it was shown that the catalysts are suitable for reuse in dye reduction. Therefore, the catalytic activity of this study suggests that the CuO nanocatalysts prepared in this work are a potential candidate for controlling organic pollutants or trace amounts of naturally occurring active organic chemicals in all environmental dye wastes.

B-doped zinc oxide/copper oxide composites prepared using a simple method showed high photocatalytic hydrogen production activity in the presence of aqueous sulfide solutions. Co-modification of the CuO composite with B-doping caused an increase in the charge separation efficiency and light absorption capacity. The sacrificial effect was thermodynamically enhanced by manipulating the composition of the sulfide solution. A maximum hydrogen production activity of 224 μmol g−1 h−1 was achieved under 450 nm light irradiation in a photocatalytic system with optimized B doping, a CuO composite, and a sulfide sacrificial agent concentration.

This work aims to design of PEO/CuO new structures and investigating optical, and electronic characteristics to use in various electronic and optoelectronics devices like diodes, transistors, photovoltaic cell, electronic gates, sensors and other electronics devices. Using the B3LYP-DFT with a suitable 6-31G basis set for pure PEO and SDD basis set for nanocomposite, a good optimization structure for the predicted nanocomposites was obtained. Geometrical values that have been calculated. The results indicated that the studied nanocomposite need small energy to become cationdue to ionization potential is decrease with addition nanoparticle to the pure PEO, but the electronic affinity is an increase with addition nanoparticles to the pure PEO. When compared to other nanocomposite, the total ground state energy of PEO has the highest value of total energy, but ET dropped with the addition of nanoparticles to pure PEO. With the addition of nanoparticles to pure PEO, the hardness decreases, making nanocomposite softer, lowering a species' barrier to losing electrons. The studied nonocomposite direct electronic transition from the valence to conduction band with wave length falls within the solar spectrum range. The results revealed that the (PEO-CuO) nanocomposite has a wide range of applications in the fields of electronics and photo-electronics.

Microwave heating (MHM) and mutated sol-gel (SGM) mechanisms were used to effectively create CuO samples with two dissimilar morphologies, such as nanoparticles (CuO-NPs) and nanorods (CuO-NRs), using Mussaendafrondosalinn plant extract as the bio-reducing operator. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) investigations were used to analyze the sample's structure, pureness, and morphological characteristics. UV-Visible diffuse reflectance (DRS) and photoluminescence (PL) spectroscopy methodologies were used to analyze optical properties and calculate bandgap energy. The bandgap of the samples was measured using the Kubelka-Munk mechanism, and it was found to be 2.74eV and 2.33eV for CuO-NPs and CuO-NRs, correspondingly. CuO-NPs and CuO-NRs were investigated for antibacterial activity versus each Gram-positive and Gram-negative microorganisms using a modified disc diffusion method. When correlated to the sample CuO nanorods, the antibacterial study confirms that the sample CuO nanoparticles are high-grade antibacterial agents. Using solar lighting, the photocatalytic activity of CuO nano-reactants (CuO-NPs and CuO-NRs) for the degradation of methylene blue (MB) dye was investigated, and the findings revealed that CuO-NPs with tinier particle sizes degraded MB more than CuONRs.

The biological fouling in polymer membranes is one of the main challenges in the membrane processes. Accordingly, CuO nanomaterials with properties such as high resistance to physical, chemical, biological agents, as well as antibacterial properties can be considered as one of the effective additives in the fabrication of composite ultrafiltration membranes, and reduce biological fouling. In this study, PVDF (16wt %), PVP (1wt %), CuO nano-plates (1wt %) were used in fabrication membranes (Phase inversion method) to increase hydrophilic properties, to reduce the membrane fouling and improve the ultrafiltration membrane filteration performance. The physical and chemical characterization of CuO nano-plates (synthesized by hydrothermal method) and fabricated membranes evaluated by XRD and FTIR analysis and also FESEM and TEM were used to study the morphology of the samples. The mixture of CuO nanoparticles with the semi-crystalline polymer structure of PVDF improved the β phase in the membrane structure which improved the hydrophilic properties of the membrane feature. The results showed that the flux and rejection of CuO nanocomposite membranes were 357 and 96% LMH, respectively, and the contact angle was about 59 degrees, which increased the hydrophilic properties of the surface by 25% compared to the control sample. The recovery rate of CuO nanocomposite membrane was about 83%, which indicates the effect of antibacterial properties of these nano-plates. Finally, BSA solution and municipal wastewater were used to evaluate the performance of nanocomposite membrane in filtration and purification. PVDF/CuO composite membrane had high efficiency in disinfection and wastewater treatment; The COD of the treated effluent was less than 5 mg/L and the removal of turbidity and TSS was about 99% and no fecal coliforms were detected.

The addition of metal oxide nanoparticles to fluids has been used as a means of enhancing the thermal conductive properties of base fluids. This method formulates a heterogeneous fluid conferred by nanoparticles and can be used for high-end fluid heat-transfer applications, such as phase-change materials and fluids for internal combustion engines. These nanoparticles can enhance the properties of both polar and nonpolar fluids. In the current paper, dispersions of nanoparticles were carried out in hydrocarbon and aqueous-based fluids using molecular dynamic simulations (MDS). The MDS results have been validated using the autocorrelation function and previous experimental data. Highly concurrent trends were achieved for the obtained results. According to the obtained results of MDS, adding CuO nanoparticles increased the thermal conductivity of water by 25% (from 0.6 to 0.75 W·m−1·K−1). However, by adding these nanoparticles to hydrocarbon-based fluids (i.e., alkane) the thermal conductivity was increased three times (from 0.1 to 0.4 W·m−1·K−1). This approach to determine the thermal conductivity of metal oxide nanoparticles in aqueous and nonaqueous fluids using visual molecular dynamics and interactive autocorrelations demonstrate a great tool to quantify thermophysical properties of nanofluids using a simulation environment. Moreover, this comparison introduces data on aqueous and nonaqueous suspensions in one study.

Abstract Due to the significant friction-reduction and anti-wear properties of nano particle, nano copper oxide (CuO) particle decorating on boron nitride nanosheets (BNNS) nanocomposites are fabricated with polydopamine (PDA) as the linking agent. The structural and morphological characteristics of the CuO@BNNS composite are characterized by scanning electron microscopy (SEM), X-ray diffraction patterns, fourier transform infrared spectroscopy and thermogravimetric analysis. The synergistic effect of CuO and BNNS on extreme pressure of lubrication oil are investigated. A four-ball tribometer is adopted to investigate the tribological behaviors of the as-prepared oil with different additives. Optical microscope and SEM are used to analyze the topography of worn surface. Energy dispersive spectroscopy is adopted to investigate the element distribution on worn surface. The results demonstrate that the CuO@BNNS nanoparticle could effectively improve the friction-reduction and anti-wear properties of the paraffin liquid, compared to paraffin liquid containing modified CuO (f-CuO) or PDA-BNNS respectively. The worn surface of steel ball presents smooth morphology for oil containing CuO@BNNS, contrast to oil containing f-CuO or PDA-BNNS respectively. With the tribo-film formation on the worn surface, the elements distribute uniformly on the worn surface for oil containing CuO@BNNS. Compared to lower load, the effect of load-carrying capacity and easy-shear property of CuO@BNNS outstand under 392 N, which results in the smooth worn surface compared to oil containing other additives. Article Highlights CuO@BNNS hybrid nanoparticle was prepared with a simple and mild method. CuO@BNNS presents superior anti-friction and anti-wear properties due to the synergistic effect of nanoparticle. The result obtained in the paper promotes the application of h-BN based nanocomposites in tribology.

In this theoretical–experimental study, the basic parameters effect such as solid volume fraction (SVF or φ) and temperature on thermal conductivity (TC) of SWCNT-CuO (25:75)/water nanofluid (NF) has been investigated. The used NF in this study has been prepared and used for the first time. Monitoring and investigation of TC were done in T = 28 to 50˚C and SVF = 0.03 % to 1.15 %. The role of SVF effective in relative thermal conductivity (RTC) with changing of the temperature shows the importance of this factor in improving the RTC; results show that the better TC is T = 50 °C compared to other temperatures. Also, the maximum enhancement of TC compared to the base fluid (BF) (36 %) was observed at the mentioned temperature. In addition to the laboratory tests such as the margin of deviation (MOD) and RTC sensitivity within the range of −1.90 %

The structural properties of the CuO nanopowder oxide prepared reflux technique without any templates or surfactant, using copper nitrate hydrate (Cu(NO)3 3H2O) in deionized water with aqueous ammonia solution are reported. The Xrd analysis data and processing in origin pro program used to get FWHM and integral width to study the effect of different synthesis times was studied on the structural properties. It was found that values of crystal sizes are 17.274nm, 17.746nm, and 18.560nm, the size of nanoparticles is determined by Halder-Wagner, and 15.796 nm, 15.851nm, and 16.52nm, were calculated by Size-Strain Plot (SSP) method. The Sample was considered to determine physical and microstructural parameters such as internal strain, dislocations density, surface area, and the number of unit cells and then to compare the results.