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Hydrogen and renewable fuels were generated using cost-effective and efficient electrocatalysts for water splitting. In this work, a CuO-based photocathode is used for the water splitting to generate hydrogen energy by PVD technique. The XRD analysis reveals the deposition of CuO thin film on ITO substrates, which is monoclinic. The XRD and LSV analysis of CuO confirmed the type of semiconductor and observed to be P-type semiconductor. SEM study of CuO confirmed the shape, morphology to be a circular and regular shape. The grain size of deposited CuO thin film was found to be 18 nm. The absorption and transmission of CuO thin film were observed through UV spectroscopy analysis and were found to be better photocatalyst in visible range 415-425 nm. The transmittance of the prepared thin film was noted to be maximum 7.6% in the UV range (280-300 nm). The band gap was also measured employing the Tauc plot and found to be 2.98 eV, which is most favorable for water splitting application. FTIR study showed the stretching, vibration, and the functional group of the deposited CuO thin film; the broad band of stretching of Cu-O in monoclinic CuO was observed at the range of 500-700 cm -1 , and further peaks were also noted at the range of 1500-1600 cm -1 . The linear sweep voltammetry (LSV) of CuO thin film was calculated in the absence of solar spectra and the presence of solar spectra and observed to be enhanced in current under solar spectra. The solar light to hydrogen emission percentage (STH %) of CuO through LSV was observed to be 2.04% under solar spectra. The low Nyquist curve of blank ITO and CuO-coated ITO substrate via electrochemical impedance spectroscopy (EIS) analysis was observed, which confirmed the enhancement of EIS of CuO-coated ITO. The hydrogen generation rate was also calculated by electrochemical cell and observed to be 5325.21 mol g -1 for 6 h., (© 2024 John Wiley & Sons, Ltd.)

The use of metal and metal oxide nanoparticles is frequently regarded as a potential solution to the issue of bacterial antibiotic resistance. Among the proposed range of nanoparticles with antibacterial properties, copper oxide nanoparticles are of particular interest. Although the antibacterial properties of copper have been known for a considerable period of time, studies on the effects of copper oxide nanomaterials with respect to biological systems have attracted considerable attention in recent years. This review presents a summary of the antibacterial properties of copper oxide nanoparticles, the mechanisms by which the antibacterial effect is realized, and the key reported methods of modifying these nanoparticles to improve their antibacterial activity. A comparative analysis of the effectiveness of these nanoparticles is presented depending on the type of microorganism, the shape of the nanoparticles, and the Gram classification of bacteria based on data from published sources. In addition, the review addresses the biological activities of copper oxide nanoparticles, including their antifungal and cytotoxic properties, as well as their "antioxidant" activity. According to the conducted analysis of the literature data, it can be concluded that copper oxide nanoparticles have a significant bacteriostatic potential with respect to a wide range of microorganisms and, in some cases, contribute to the inhibition of fungal growth. At the same time, the sensitivity of Gram-positive bacteria to the effect of copper oxide nanoparticles was often higher than that of Gram-negative bacteria.

The speedy growth of copper oxide nanoparticle (CuO NP) manufacturing due to their wide application in industries has caused concerns due to their increased discharge into the environment from both purposeful and accidental sources. Their presence at an elevated concentration in the environment can cause potential hazards to the plant kingdom, specifically to staple food crops. However, limited research is available to determine the consequences of CuO NPs. The present study aimed to assess the morphological and cytological changes induced by CuO NPs on Pisum sativum L., a key staple food crop. Seeds of Pisum sativum were exposed to various concentrations of CuO NPs (0, 25, 50, 75, 100, and 125 ppm) for 2 h, and their effects on seed germination (SG), radicle length (RL), cell proliferation kinetics (CPK), mitotic index (MI), cell death (CD), micronucleus frequency (MNF), and chromosomal aberration frequency (CAF) were studied. The results indicate a significant reduction in SG, RL, CPK, and MI and a significant dose-dependent increase in CD, MNF, and CAF. CuO NP treatment has led to abnormal meiotic cell division, increased incidence of micronucleus frequency, and chromosomal aberration frequency. Additionally, the CuO NP-treated groups showed an increase in the percentage of aberrant meiotic cells such as laggard (LG), double bridge (DB), stickiness (STC), clumped nuclei (CNi), precocious separation (PS), single bridge (SB), and secondary association (SA). CuO NP treatment led to reductions in SG as follows: 55% at 24 h, 60.10% at 48 h, and 65% at 72 h; reductions in RL as follows: 0.55 ± 0.021 cm at 24 h, 0.67 ± 0.01 cm at 48 h, and 0.99 ± 0.02 cm at 72 h; reductions in CPK as follows: 34.98% at prophase, 7.90% at metaphase, 3.5% at anaphase, and 0.97% at telophase. It also led to a 57.45% increase in CD, a 39.87% reduction in MI, and a 60.77% increase in MNF at a higher concentration of 125 ppm. The findings of this study clearly show that CuO NPs have a genotoxic effect on the food crop plant Pisum sativum.

Herein, novel nanocomposites based on reduced graphene oxide decorated copper oxide nanoparticles (rGO/CuO) were prepared by the in situ co-precipitation method. The structural, morphological, and optical characterization of as-prepared nanocomposites was performed by powdered x-ray diffraction (p-XRD), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR), Raman, and ultraviolet-visible (UV-Vis) spectroscopy, respectively. The as-prepared nanocomposites exhibited better photocatalytic activity of rhodamine B dye with maximum ~94% degradation in 120 min with a rate constant of 0.2353 min -1 under optimized conditions. Furthermore, the effects of solution pH and catalyst loading are studied on the degradation process. Therefore, this state-of-the-art strategy for the decoration of CuO nanoparticles onto the surface of rGO nanosheets could be an ideal platform for fabricating highly efficient photocatalysts., (© 2024 Wiley Periodicals LLC.)

Виготовлено тонкі плівки CuO методом реактивного магнетронного розпилення при постійному струмі в універсальній вакуумній установці Leybold-Heraeus L560 на скляні підкладки, температура яких складала 300 К та 523 К. Досліджено структурні, електричні та оптичні властивості для отриманих зразків тонких плівок CuO, а саме було визначено: елементний склад, представлено розподіл елементів на поверхні, які входять до складу даних плівок, розмір зерен, енергію активації, оптичну ширину забороненої зони, показник заломлення, проведений аналіз кривих спектрів пропускання і відбивання для плівок СuO, нанесених на скляні підкладки. Елементний склад тонких плівок та морфологію поверхні отримано за допомогою скануючого електронного мікроскопа (MIRA3 FEG, Tescan) оснащеного детектором відбитих електронів (BSE) і енергодисперсним рентгенівським детектором (EDX). Встановлено, що розмір зерен для плівок отриманих при нижчій температурі підкладки D становить ~ 16 нм, а для плівок отриманих при вищій температурі – D ~ 26 нм. На дифрактограмах тонких плівок CuO спостерігається більша інтенсивність піків для тонких плівок отриманих при вищих температурах підкладки CuO №2, що може бути зумовлено кращою структурною досконалістю тонких плівок та більшим розміром зерен. З дослідження електричних властивостей, встановлено, що температурні залежності електричного опору для тонких плівок CuO мають напівпровідниковий характер, тобто опір зменшується при збільшенні Т. Чотирьохзондовим методом виміряно величини поверхневого опору плівок: зразок №1 - ρ = 18,69 кОм/¨, зразок № 2 –‑ ρ = 5,96 кОм/¨. На основі незалежних вимірювань коефіцієнтів відбивання і пропускання визначили оптичну ширину забороненої зони (Egop) для двох зразків екстраполяцією прямолінійної ділянки кривої (αhν)2 = f (hv) на вісь hv. Для зразка CuO №1 Egop = 1,62 еВ; для зразка CuO №2 Egop = 1,65 еВ. Для тонких плівок CuO №2 також використовували конвертний метод для визначення основних оптичних коефіцієнтів Egop = 1,72 еВ, отримані значення Egop визначені двома методами добре корелюють між собою.

The pure CuO nanofibers were synthesized via the electrospinning method successfully. The calcinated CuO nanofibers were investigated for sensing hydrogen and carbon monoxide gases. Structural properties of the synthesized calcinated nanofibers were studied using Fourier –transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX), and particle morphology by scanning electron microscopy (SEM). SEM images confirmed string-like structures, nanofibers. The sensor based on the calcinated CuO nanofibers exhibited excellent gas sensing performance at the low operating temperature of 175 °C and the fast response and recovery characteristics at a low concentration. Moreover, good stability, prominent reproducibility, and excellent selectivity are also observed based on the calcinated nanofibers. These results demonstrate the potential application of calcinated CuO nanofibers for sensing hydrogen (10–200 ppm) and carbon monoxide (400–700 ppm) gases.

In this paper a humidity sensor based on CuO has been successfully fabricated. Thin film of CuO nanorices were synthesized by Successive Ionic Layer Adsorption and Reaction (SILAR) method on silicon wafer with Si3N4thinlayer as a substrate. The microstructure and morphology of the samples were investigated using X-ray diffraction(XRD) and scanning electron microscopy (SEM). Humidity sensing properties of the thin films have been studied. The sensing response has been measured in the relative humidity (RH) range from 20 up to 80 % at room temperature. It was found that impedance of the system decreases as the RH was increased. The prepared sensor revealed good reversibility with response and recovery time of 130 s and 320 s respectively. The complex impedance spectra were analyzed in the range of 0.1 to 1 kHz. This type of humidity sensor can be used as a new generation of ecological sensors with low cost and good stability. It makes the sensor a candidate for practical applications.

Energy consumption for building cooling is directly related to incident solar radiation. Therefore, solutions of high reflectivity, while keeping color comfort, are being actively researched. Here, finite-difference time-domain (FDTD) simulations were used to investigate the influence of nanoparticle and core–shell additives on coating reflection and color. Different TiO2 and CuO nanoparticle mixings were tested, with relative concentrations varying from 0 to 20% of each on acrylic. The same compounds were used to define core–shells with a varied inner radius (0–30 nm) for both TiO2 and CuO as the core and shell. The numerical simulations demonstrate that mixing CuO with TiO2 enables dark colors while maintaining the overall reflectance. The reflectance results for the core–shell structure are comparable with those of the nanoparticles when CuO is the core, while a more pronounced color change is originated when CuO is the shell.

Indonesia is the larger pineapple producer country in the world, so they have the potential to generate biomass waste from the peel. Pineapple peel content is a carbon source in the fermentation process for producing bacterial cellulose. Some nanomaterials such as TiO2 and Graphene oxide has been increased the adsorption of ion metal and water purification in nanocomposite membranes. CuO nanomaterial has functioned as an antibacterial material in biomedical applications. So, this study aimed to evaluate the effect of adding CuO nanoparticles (CuO-NPs) to the characteristic of bacterial nanocellulose-based membranes made of pineapple peel waste. The methods include synthesizing bacterial cellulose from pineapple peels and producing bacterial nanocellulose in a high-speed blender and a nano-homogenizer. Raw materials such as BC, CTAB, and CuO-NPs (concentrations of 1.0% and 2.0%) were mixed and homogenized using an ultrasonic homogenizer, then filtered and freeze-dried at -62oC for two days to obtain a membrane. Using SEM, XRD, FTIR, surface roughness, and tensile tester we can see the addition of CuO-NPs can affect the characteristic of BC/CuO nanocomposite. SEM Results show that the surface morphology containing a lower concentration of CuO-NPs has better homogeneity dispersion. From XRD analysis, by addition, CuO-NPs can be appearing new peaks at 35.47o and 38.68o, but it reduces the degree of crystallinity, crystallinity index, and Crystalline size of the membrane but increases its surface roughness. Adding CuO-NPs to the BC structure causes a shift and change of transmittance value that indicate the interaction of CuO to BC fibril. The highest tensile strength of nanocomposite membrane is 69.643 MPa, obtained from a lower concentration of CuO-NPs. [ABSTRACT FROM AUTHOR]

In this research, bare, graphene oxide (GO) and reduced graphene oxide (rGO)-doped nanostructured copper oxide (CuO) thin films have been deposited on soda-lime glass substrates using low-cost and easy solution-based successive ionic layer adsorption and reaction (SILAR) method. The victoriously produced films were characterized to understand the effect of GO and rGO content on the crystalline structure, surface morphology, and optical properties of the CuO samples by different characterization methods. The obtained results showed that GO and rGO doping heavily affected the main physical characteristics of CuO nanostructures. XRD measurements confirmed the sharp, monoclinic CuO phase with the preferred orientation (002) and (112). The estimated crystallite size of samples is changed with GO and rGO doping as 7.63, 8.37, and 8.50 nm for the bare, GO, and rGO-doped CuO films, respectively. FE-SEM and SPM results exhibited that film morphology is influenced by the GO and rGO doping. The FTIR and Raman spectra of CuO have an ordinary stretching vibration mode of the metal–oxide bonds and the presence of GO/rGO led to the change of peaks of this structure. The optical bandgap energy of bare CuO was found to be 1.47 eV and it decreased to 1.32 eV as a result of rGO doping which is good sufficient for solar window applications. The sheet resistance value decreased with the GO doping from 7.87 × 109 to 2.72 × 109 Ω/sq. The obtained results signify that the doping of GO and rGO in CuO thin films are responsible for the regulation of the main physical properties of nanostructured materials as electronic and optoelectronic materials. [ABSTRACT FROM AUTHOR]

The physical properties of pure CuO and Pb doped CuO thin films, deposited on glass substrates by a sol-gel method, were investigated. Structural analysis revealed the polycrystalline nature of the pure CuO and Pb:CuO composite films with a monoclinic structure, the crystallite size decreased and ranged from 36.78 nm to around 21.5 nm. The SEM images of the CuO thin films showed that the Pb doping concentration affects the surface morphology of the Pb:CuO composites. The absorbance of the Pb:CuO composites is higher than that of the undoped CuO thin films. The optical band gap energies of undoped CuO and Pb doped CuO thin films were estimated to 1.9 (pure), 2.17(5%) and 2.74 (7%)eV, and found that the band gap energy (Eg) increases with the Pb concentration. This blue shift is due to the quantum confinement induced by the reduction in the size of the crystallites. [ABSTRACT FROM AUTHOR]

A green method for depositing a CuO layer with good adhesion and a large surface area on a support of activated alumina (Al2O3) was evaluated. The relatively simple method consists of adsorption of a copper salt on the surface of Al2O3, formation of Cu(OH)2, and subsequent decomposition of the hydroxide to CuO. The XRD confirmed that the deposited photocatalyst crystalized at low temperatures (80 °C). Furthermore, BET measurements show a surface area of about 90 m2/g. The large surface area is the result of the speed of the conversion and decomposition reactions. The photokilling properties of the prepared photocatalyst were evaluated using E. coli cells and the leaching of copper ions was determined using ICP-MS. The photocatalytic efficiency was also evaluated by the degradation of an organic azo dye. The prepared photocatalyst shows good activity in the purification and disinfection of treated water. The described method is economical, fast, and can be considered green, since the only byproducts are water and NaCl. [ABSTRACT FROM AUTHOR]

A heterogeneous catalyst CuO–CeO2 with a hollow structure was successfully synthesized by assembling CuO on the outer surface of CeO2 hollow spheres through a layer-by-layer deposition strategy. Further reduction under a H2 atmosphere was carried out to modify its surface state, resulting in sample r-CuO–CeO2. The catalysts were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform-infrared spectroscopy (FT-IR). SEM and TEM showed that the synthesized catalysts had a hollow sphere structure, which can expose more active sites and promote mass transfer. The results of XPS revealed that the content of Cu0&Cu+ increased from 13.6 to 19.0% after H2 reduction, which was conducive to the activation of terminal alkyne to promote the annulation/A3-coupling reaction. The conversion of this cascade reaction with the r-CuO–CeO2 catalyst can reach more than 95%, while the value was only 55% by using CuO–CeO2 as a catalyst. Moreover, the r-CuO–CeO2 catalyst showed a good recycle property and group compatibility in the general applicability of the cascade annulation/A3-coupling reaction, providing a series of propargylamine derivatives in good chemoselectivity. [ABSTRACT FROM AUTHOR]

Copper oxide (CuO) nanostructures have demonstrated a good chemiresistive response for the sensing of various gases. The precise sensing mechanisms of this material and, in particular, the kinetics of the response to gases and the sensor recovery remain much less investigated. For metal oxide (MOx) chemiresistive gas sensors, oxygen adsorption and desorption reactions on a material surface play a major role in the sensor kinetics, as most other gases react with oxygen on the sensor surface in order to provide the sensing signal, and nanoscale materials are known to achieve faster response. Here we investigate the oxygen adsorption and desorption kinetics on CuO nanowire bundle (NWB) networks by analyzing the electrical response and recovery curves of sensing devices exposed to oxygen. The observation of multiple time constants for the response and recovery curves led us to discuss the various potential mechanisms related to surface reaction kinetics and diffusion of oxygen species. By comparing the reaction rate constants and diffusion constants extracted from the obtained time constants, we conclude that the diffusion of oxygen defects into the material might be the main reason for the observed large time constants. Surprisingly, we observe that the sensor devices based on as-deposited materials show 4–16 times faster response and recovery as compared to devices after being annealed, depending on the temperature. By comparing this result with detailed characterization using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, we discuss the role of the junctions between nanostructures in the network and of the hydroxylated CuO surface to explain this result. Our investigation on the kinetics of adsorption and desorption of oxygen of CuO NWB provides a direct understanding of the general response of the sensor and will be useful in order to further understand and optimize these materials for the sensing of various gases. [ABSTRACT FROM AUTHOR]

Nanocrystalline NiO/CuO solid solutions and heterostructured powders are prepared by a sol–gel auto combustion method. Herein, the NiO/CuO compounds at various molar ratio, including 100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10, 80/20, 50/50, 20/80, 10/90, 5/95 and 0/100, are investigated. The structures, morphologies, optical, and magnetic properties of all samples are explored. The detailed structures of the NiO/CuO system are deduced from Rietveld refinements of X‐ray diffraction (XRD) data and the combination of experimental and simulation studies of X‐ray absorption spectroscopy (XAS) spectra. It is found that a small addition of CuO in NiO enhances the formation of rock salt CuxNi1–xO solid solutions with 0 ≤ x ≤ 0.1. The NiO/CuO composites with CuO mole fractions (m) of 20% ≤ m ≤ 95% are affirmed by the coexistence of NiO rock salt and CuO tenorite phases. The composites rich in CuO exhibit strong adsorption in the visible and ultraviolet spectral regions, while the absorption of composites rich in NiO is absent in certain regions of visible and infrared light. In addition, the superparamagnetism of NiO can be tuned to ferromagnetism by a small addition of CuO. The photocatalytic degradation efficiencies of rhodamine B, methylene blue, methyl orange, and methyl red over NiO/CuO reach 92%–97% within a period of 150 min under sunlight irradiation. [ABSTRACT FROM AUTHOR]

The jet nebulizer spray (JNS) pyrolysis method has been successfully employed to grow CuO thin films at various substrate temperatures, ranging from 300 to 600˚C. The XRD analyses revealed the monoclinic phased polycrystalline growth of the samples and exhibited the strong influence of substrate temperature (ST) on the crystallite sizes. Optical transmission and bandgap studies also showed that sample bandgaps clearly rely upon the growth temperatures. The SEM micrographs displayed the agglomerated growth of particles having golf ball-like structures. The occurrence of Cu and O in the samples were confirmed through EDS analyses. The studies on DC electrical conductivities (I-V curves) also show strong dependency on the ST. A p-CuO/n-Si diode was fabricated at the ST of 600˚C and the diode parameters like barrier height ( φ b ) and ideality factor (n) were determined under light and dark conditions. [ABSTRACT FROM AUTHOR]

Samples of copper-modified bioactive borate glasses were synthesized and their radiation shielding properties including gamma-ray and neutron radiation shielding were investigated. Further, the glasses' mass attenuation coefficients were measured with a NaI(Tl) detector while their gamma-ray shielding parameters were estimated using Phy-X/PSD program. Free-radical densities were measured via electron spin resonance to estimate the absorbed doses during accidental irradiation. The extensive reduction of the dose detection threshold (2 Gy) required the estimation of the signal of the non-irradiated sample. In addition, the effects of applied microwave power and absorbed dose on synthesized samples were studied. Finally, the thermal annealing of the emerging peaks, which were due to the irradiation signal-to-noise ratio and energy dependence, was studied to estimate the stabilities of such peaks. This modified material is recommended to detect and monitor the gamma-radiation dose because of its good dosimetric properties. Finally, regarding the presence of the two borate groups, triangular and the tetrahedrally coordinated, in their definite and typical wavenumbers, the FTIR spectra displayed simplified vibrations that were close to those of many bioglasses. This paper provides complementary results for the author's previous research examining this glass for low photon dose measurements using luminescence characteristics. [ABSTRACT FROM AUTHOR]

High-purity TiO2 and CuO powders were synthesized by the Pechini method, an inexpensive and easy-to-implement procedure to synthetize metal oxides. The variables of synthesis were the ethylene glycol:citric acid molar ratio and the pH. High reproducibility of the anatase and tenorite phase was obtained for all synthesis routes. The degree of purity of the powders was confirmed by XRD, FTIR, UV-Vis absorption and XPS spectra. SEM and TEM images revealed the powders are composed of micrometer grains that can have a spherical shape (only in the TiO2) or formed by a non-compacted nanocrystalline conglomerate. FTIR spectra only displayed vibrational modes associating TiO2 and CuO with nanoparticle behavior. UV-Vis absorption spectra revealed the values of maximum absorbance percentage of both systems are reached in the ultraviolet region, with percentages above 83% throughout the entire visible light spectrum for the CuO system, a relevant result for solar cell applications. Finally, XPS experiments allow the observation of the valence bands and the calculation of the energy bands of all oxides. [ABSTRACT FROM AUTHOR]

The formation, properties, decomposition and reactions of ethoxy groups on ZrO2, CuO, and CuO/ZrO2 were followed by IR spectroscopy. The reaction of ethanol with terminal Zr-OH groups leads to the formation of monodendate ethoxy groups (type I), whereas the reaction of ethanol with tribridged Zr-OH grups results in the formation of bidendate ethoxyls (type II). In both cases, water is produced. Ethoxy groups of type II were also formed on CuO. The type of the surface species detected after interaction of ethanol with CuO/ZrO2 was the same as detected for both oxides (i.e., ZrO2 and CuO) separately. This suggests that no new phase was formed in the mixed oxide system. At higher temperatures, ethoxy groups were oxidized forming acetate ions. Gaseous ethanol present in the cell was oxidized to acetaldehyde without the intermediacy of ethoxy groups. [ABSTRACT FROM AUTHOR]

In the present research, CuO nanopowders with high dispersivity were synthesised using a solution plasma method. The effect of K2CO3 as an electrolyte on the phase and morphology of the products was examined. The antibacterial activity was investigated by calculating the diameter of the inhibition zone, minimal inhibitory concentration (MIC), and minimal bactericidal concentration (MBC). The XRD results showed that the sample synthesised at a low concentration of K2CO3 had two phases of CuO and Cu(OH)2, whereas the one prepared at high electrolyte concentrations exhibited copper oxide single phase. The nanoparticles were stable and dispersed up to 10 h in water. The DLS result showed the size distribution starting from 25 to 160 nm, which confirms the powders' high quality prepared by a solution plasma method. The antibacterial result revealed that the synthesised samples are effective as an antibacterial agent to reduce Pseudomonas aeruginosa and Staphylococcus aureus activity. [ABSTRACT FROM AUTHOR]

Graphene known as the wonder material and finds its utilization in various applications including sensors.This work reports the solvothermal route and the chemical reflux method synthesis of graphene oxide copper oxide nanocomposite material (GO-CuO). The hitherto prepared GO-CuO nanocomposite was well characterized using the usual spectroscopic and microscopic technique such as Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Vis Spectroscopy (UV), Photoluminescence Spectroscopy(PL) etc. The prepared GO-CuO nanocomposite was found to selectively bind to L-Leucine without any interference from the other naturally occurring L-amino acids as a potential fluorescent chemosensor. The interference studies, effect of time, effect of pH and various equivalence studies were also performed for the GO-CuO nanocomposite with L-Leucine. The antibacterial activity of GO-CuO nanocomposite revealed a minimum inhibitory zone concentration for Methicillin Resistant Staphylococcus aureus to be 200 μg/ml, whereas for A. baumannii it was found to be 100 μg/ml. [ABSTRACT FROM AUTHOR]

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In this work, we explore the nonenzymatic detection of H2O2 using anodic SnO2 nanoporous channels (NPC) decorated with CuO quantum dots (QDs). The open-top and crack-free morphology of SnO2 NPC was obtained by modified anodization. The samples were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray analysis (EDAX), high-resolution transmission electron microscopy (HRTEM), Raman and X-ray photoelectron (XPS) spectroscopy. FESEM and HRTEM results show that SnO2 has a uniform channel width and pore size with an average diameter of around 40 nm. XRD, EDAX, XPS, Raman, and HRTEM measurements confirm the high purity of anodic SnO2 NPC with successful deposition of CuO QDs. Pristine (SnO2) and hybrid (SnO2-CuO) electrodes were used directly as the nonenzymatic H2O2 biosensor. The hybrid electrode demonstrated an ultrahigh sensitivity of ∼85,250 μA mM–1 cm–2 with an extremely low limit of detection (0.001 μM), broad linear detection ranges of 5–95 and 25–450 μM, and a quick response time (less than 1.9 s) toward H2O2 detection. This can be attributed to the advanced SnO2 nanoporous structure, the reduced band gap, and the formation of additional surface sites as a result of CuO QD decoration. H2O2 measurement in human blood serum demonstrates high sensitivity, good accuracy, and excellent selectivity of the fabricated hybrid electrode compared to the commercially available biosensor. Density functional theory results indicate that the formation of SnO2-CuO is energetically favorable. H2O2 is strongly and selectively adsorbed over the SnO2-CuO nanostructure possessing a large negative adsorption energy (−1.89 eV) and evinces a significant decrease in the band gap (up to 1.59 eV) of the hybrid structure. The fabricated biosensor showed the highest sensitivity, excellent selectivity, good reproducibility, repeatability, and stability, thus confirming it as a favorable candidate for nonenzymatic H2O2 sensing and quantification. [ABSTRACT FROM AUTHOR]

Herein, a ternary Bi 2 O 3 –CuO–CuBi 2 O 4 photocatalyst was synthesized by the solvothermal deposition via the adjustment of Cu/Bi concentration ratio. The Bi 2 O 3 –CuO (5%) with the 5% of Cu/Bi concentration ratio exhibited dramatically high solar/visible light-driven photocatalytic activity, and the photocatalytic rate was 2.69/2.06 and 2.39/1.75 folds of pure Bi 2 O 3 photocatalysts toward rhodamine B (RhB) and methylene blue (MB) photodegradation, which was ascribed to the high solar absorption and low interface resistance. In addition, the •O 2 − and •OH radicals were defected to be the active species for the dye degradation, and then the Z-scheme heterojunction scheme was proposed to explain the photocatalytic result. The prepared sample photoelectrode also displayed the attractive photoelectric conversion capacity. The investigation indeed confirms that the novel ternary Bi 2 O 3 –CuO–CuBi 2 O 4 photocatalysts exhibit wide application prospect in wastewater remediation. [ABSTRACT FROM AUTHOR]

Copper oxide and hematite (CuO/α-Fe2O3) composite catalysts were prepared by using goethite as precursor adopted impregnation way and applied to the dielectric barrier discharge (DBD) catalytic decomposition of gaseous chlorobenzene. The CuO/α-Fe2O3 composite was characterised by X-ray diffraction, Brunauer–Emmett–Teller method, scanning electron microscopy and X-ray photoelectron spectrometer technique. The decomposition efficiency and energy yield of gaseous chlorobenzene in DBD catalysis system were studied by a function of gas flow rate, initial concentration and input voltage. The results showed that the CuO/α-Fe2O3 composite catalyst exhibited remarkable performance on chlorobenzene decomposition when the molar ratio was 0.4 and calcination temperature was 450°C. When the chlorobenzene initial concentration was 230 mg m−3, the chlorobenzene decomposition efficiency and mineralisation rate on the DBD catalysis system reached 73.33% and 63.37%, respectively, its decomposition and mineralisation efficiency were enhanced about 20.5% and 16.61%, respectively, compared with the bare DBD system, and it also benefited to significantly reduce the ozone and NO2 by-products. The possible pathway of chlorobenzene decomposition in the DBD catalytic hybrid system was proposed based on the products analysis. [ABSTRACT FROM AUTHOR]

A successful drilling operation requires an effective drilling fluid system. This work aims to provide an effective solution for improving the rheological and filtration properties of a water-based drilling fluid using a CuO nanofluid additive. CuO nanoparticles were synthesized by a hydrothermal method using an autoclave, which can control the temperature and pressure. Then, a CuO nanofluid (eco-friendly ethylene glycol based) was produced as a drilling fluid additive. X-ray diffraction, Fourier-transformed infrared spectroscopy, and scanning electron microscopy were used to characterize the nanoparticles. The results confirmed the formation of the high-purity CuO nanoparticles forming a wire shape structure. The experimental design method optimized the operating parameters, and two long-time stabilized nanofluids were prepared to improve the rheological properties and the fluid loss of a polymeric water-based drilling fluid based on the optimal results. Xanthan, polyanionic cellulose, and starch are commonly used to improve rheological and fluid loss properties in drilling fluids. Further, the effect of the pH level of the nanofluids on the improvement in the water-based drilling fluid properties was investigated. The results showed that the nanofluid with a pH of 8.0 could be used as the best additive to improve the drilling fluid properties. The yield point, apparent viscosity, 10 s and 10 min gel strengths of the drilling fluid, and the fluid loss improved by 45%, 33%, 200%, 100%, and 44%, respectively. [ABSTRACT FROM AUTHOR]

The photoluminescence properties of glasses have attracted much interest in the recent trends of technology. Glass can provide a suitable host environment for transition metal or rare earth ions as a powerful activator to achieve the desired luminescence. In this work, a new system of Eu3+- and Cu2+-doped borogermanate glass with composition of 80% B2O3:20% GeO2 was prepared. The formed glass systems were studied via optical, photoluminescence, XRD and FTIR spectral measurements. The XRD results confirmed the amorphicity and unstructured nature of the prepared samples. The optical absorption spectra revealed no characteristic spectrum in the visible region for the undoped glass, while the CuO-doped glasses demonstrated absorption in a broad band centered at about 770 nm, and the Eu2O3-doped samples showed two visible absorption peaks at 475 and 542 nm. The optical band gap result for GCu-Eu was lower than that for GCu and GEu. The photoluminescence spectrum showed stable blue emission for the undoped glass, which was enhanced with Cu2+ and Eu3+ addition. The color coordinates by CIE chromaticity diagram indicated the blue emission of all samples with a slight variation in positions. The FTIR measurements revealed the existence of a combination of the two borate groups (BO3) and (BO4) besides the Ge-O groups (GeO6, GeO4), with no distinct effect of dopants. The presence of CuO and Eu2O3 affected the density of the borogermanate glass according to the molecular weight and ionic radii of both ions. [ABSTRACT FROM AUTHOR]

Electrode structure is an essential factor affecting the performance of flexible humidity sensors. In this study, Cu and Cu2 + 1O electrodes were printed by the one-step method using laser direct writing technology to reduce the nano–CuO ink on flexible substrate PI and to be used for a humidity sensor. The resistance of the humidity sensors with nine various electrode structures was measured under the relative humidity (RH) of 16–78%. It was observed that all sensors showed good humidity sensing characteristics, and the sensitivity of the copper-based humidity sensor was not affected by the electrode structure under low humidity conditions but was significant under high humidity conditions. The sensor with the length of 1960 μm and the width of 120 μm shows the lowest sensitivity of 180.2 KΩ/%RH under 35% RH, and the sensor with the length of 2430 μm and the width of 180 μm shows the highest sensitivity of 1744 kΩ/%RH under 65% RH. It is expected that the results can provide an assessment of the performance improvement of the flexible humidity sensor and a reference for the research and development of intelligent wearable devices. [ABSTRACT FROM AUTHOR]

Electrocatalytic ammonia oxidation reaction (EAOR) provides an ideal solution for on-board hydrogen supply for fuel cells, while the lack of efficient and durable EAOR catalysts has been a long-standing obstacle for its practical application. Herein, we reported that the defect engineering via in-situ electrochemically introducing oxygen vacancies (Vo) not only turns the inactive CuO into efficient EAOR catalyst but also achieves a high stability of over 400 h at a high current density of ∼ 200 mA·cm−2. Theoretical simulation reveals that the presence of Vo on the CuO surface induces a remarkable upshift of the d-band center of active Cu site closer to the Fermi level, which significantly stabilizes the reaction intermediates (⋆NHx) and efficiently oxidizes NH3 into N2. This Vo-modulated CuO shows a different catalytic mechanism from that on the conventional Pt-based catalysts, paving a new avenue to develop inexpensive, efficient, and robust catalysts, not limited to EAOR. [ABSTRACT FROM AUTHOR]

[Display omitted] • MOF derived erythrocytic-like nanoflower CuO@N/C-ZnO was obtained for first time. • CuO@N/C-ZnONF yields high CO and CH 4 outputs of 286.16 and 39.74 umol g−1h−1. • The enhanced photoreduction of CO 2 was attributed to distinctive heterostructure and abundant active sites. In this pioneering work, an innovative photocatalyst, denoted as the porous erythrocytic-like nanoflower derived from zeolitic imidazolate framework (ZIF-8) (CuO@N/C-ZnONF), has been meticulously crafted. This design integrates a porous nanosheet of nitrogen and carbon co-doped ZnO, strategically refined with CuO nanosheets (CuONS) architecture originating from ZIF-8. This innovative nanomaterial serves as a nanoreactor for converting CO 2 into CO and CH 4. The distinctive porous nanoflower structure facilitates enhanced mobility of charge carriers throughout the accessible framework, maximizes exposure of active sites, and improves the flow of charge carriers while preventing their recombination. Additionally, the porous characteristics facilitate the diffusion of reactants and products. The synthesized 10CuO/N-C-ZnONF demonstrates superior photocatalytic performance, yielding high CO and CH 4 outputs of 286.16 and 39.74 µmol g−1h−1, respectively, and exhibits excellent long-term stability. [ABSTRACT FROM AUTHOR]

To develop materials that can meet the sensing and capacitive performance of glucose. Hydrothermal and electroplating procedures were used to prepare linear NiCo 2 O 4 and nano-CuO particles, respectively. The sensor's sensitivity was 1174.57 μA mM−1 cm−1, with a low detection limit of 0.024 μM (S/N = 3), and its detection range was 0.3–12.6 mM, with good stability as verified using an electrochemical workstation. In addition, at a current density of 2 A g−1, this material exhibits a specific capacitance of up to 2140.0F g−1 in supercapacitors. After 5000 cycles, its stability remained at 93.89 %. Similarly, asymmetric supercapacitor devices based on nickel foam exhibit A high specific capacitance of 605.5 F g−1 at a current density of 2 A g−1. It is demonstrated that linear NiCo 2 O 4 modified with CuO nanoparticles can be employed not only as a sensitive material for glucose sensors but also for the production of supercapacitors. • Convenient operation, simple preparation, mass production as glucose sensor. • High specific capacitance as a supercapacitor. • The material was tested for glucose sensors and supercapacitors with excellent performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fabrication of binder-free Cu/Cu(OH) 2 nanowire bundles electrodes via simple anodization. • Anodization at 0.1 mV/s yielded the highest capacitance of 22.5 mF/cm2 at 1 mA/cm2. • The electrode retained 120% of capacitance after 10,000 charge–discharge cycles. • Phase transformation from Cu(OH) 2 nanowire bundles to CuO nanosheets observed after cycling stability tests. • Strong correlation between supercapacitor performance, electrode surface morphology and diffusion coefficients (D). In this work, a binder-free Cu/Cu(OH) 2 NwBs electrode was fabricated using a simple potentiodynamic anodization method. The effect of anodization scan rates of 3, 0.5, and 0.1 mV/s on the structural, morphological, and supercapacitive properties was thoroughly investigated. An areal capacitance of 22.5 mF/cm2 at 1 mA/cm2 was achieved at scan rate of anodization 0.1 mV/s. The Cu/Cu(OH) 2 electrode demonstrates excellent retention cyclic stability of 120 % after 10,000 cycles. Post-cycling analysis revealed a phase transformation from Cu(OH) 2 to CuO, accompanied by significant morphological changes. A theoretical model based on Fick's law was employed, which aligned well with the experimental data. The diffusion coefficient values were calculated from charge/discharge data, and the results indicated that higher diffusion coefficients corresponded to higher specific capacitance, demonstrating improved supercapacitor performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • HZSM-5 support with cavity structure was prepared using an "dissolution–recrystallization" process. • The catalytic activity of 12CuO/HZ-T 0.7-150-72 is better than that of 12CuO/HZ. • Confinement of active components within the support cavities prolongs catalyst lifespan. • TPAOH treatment introduced more basic sites to facilitate AsH 3 removal. • AsH 3 was eventually oxidized to arsenic-containing oxides. The accumulation of arsenic-containing oxides is a critical factor in the reduced activity of catalysts for arsine (AsH 3) removal. In this study, we successfully synthesized a hollow-structured molecular sieve support (HZ-T) for CuO loading (12CuO/HZ-T), significantly enhancing AsH 3 catalytic oxidation efficiency and stability. The optimized catalyst (12CuO/HZ-T 0.7-150-72) exhibited substantially higher AsH 3 catalytic activity than the conventional catalyst (12CuO/HZ) at 100 and 140 °C, maintaining 100 % AsH 3 removal for over 167 h at 140 °C. Systematic characterization revealed that the superior AsH 3 catalytic performance of 12CuO/HZ-T 0.7-150-72 is attributed to the confinement of active components within the support's cavities, addressing the rapid deactivation caused by arsenic-containing oxide coverage. Additionally, basic sites introduced by tetrapropylammonium hydroxide (TPAOH) treatment further promoted AsH 3 removal efficiency. [ABSTRACT FROM AUTHOR]

Quantum dots (QDs) have recently received much attention as photocatalysts due to their unique properties. Despite the advantages reported for QDs as photocatalysts in literature, their sonophotocatalytic/photocatalytic activity is still hindered by a series of barriers, which limit them to operate after several successive cycles efficiently. The main aim of this work is to fabricate an efficient and recyclable sonophotocatalyst/photocatalyst using ZnO quantum dots (ZQDs), tenorite (CuO), and graphene (G). In this regard, different amounts of ZQDs (ZQDs(x)/G, x= 10, 20, 30, 40, and 50 mg) were immobilized on graphene by hydrothermal method and various weight percent of CuO was impregnated on ZQDs(40)/G. The PXRD patterns and Raman spectra confirmed the wurtzite and monoclinic crystal structure for ZQDs and CuO, respectively. Also, FESEM, AFM, and PXRD showed that the mean crystal size of ZQDs increased after immobilization on graphene and impregnation by CuO. PL and Mott–Schottky analyses showed that the presence of GO and CuO in CuO(0.5)/ZQDs(40)/G reduced the recombination of excitons and formed p-n heterogeneous junctions between CuO and ZnO. The VB and CB potential and bandgap energy were obtained using DRS and Mott–Schottky analyses, and the mechanism of tetracycline (TC) degradation was proposed according to active species trapping and H 2 O 2 paper testes. The apparent rate constant (kapp) was 0.030 and 0.060 min−1 for photocatalytic and sonophotocatalytic degradation of TC in the presence of CuO(0.5)/ZQDs(40)/G, respectively. The treated effluent of TC showed acceptable performance in growing wheat seeds. The electricity cost estimation showed that (CuO(0.5)/ZQDs(40)/G) consumed less electricity in sonophotocatalytic/photocatalytic TC degradation and could also be used in several successive cycles. Finally, two RF and AdaBoost models based on ML algorithms were developed to predict photocatalytic/sonophotocatalytic degradation. The results showed that the values of statistical metrics, including SAE, MAE, MSE, and RMSE, for the AdaBoost model were relatively lower than those for the RF model, indicating better prediction performance in train and test datasets. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, we investigate the influence of ZnO capping on CuO films deposited by spray pyrolysis and its subsequent impact on the photo-response of Ag/CuO/Ag photodetector. Our findings demonstrate that ZnO capping significantly affects the electrical properties of CuO film. This is manifested as a substantial decrease in dark-current (from 12.06 μA to 0.49 μA), a pronounced increase in photo-current (from 28 μA to 665 μA), and a rapid photo-response time of 3.2 ms. These enhanced electrical characteristics translate to superior photodetector performance, as evidenced by increased responsivity (0.9 A/W), detectivity (5 × 1011 Jones), sensitivity (2.4 × 104 %), and external quantum efficiency (132 %) compared to the bare CuO device (0.11 A/W, 1.3 × 1010 Jones, 132 %, and 17 %, respectively). These results highlight the promising potential of ZnO-capped CuO films for application in high-performance infrared photodetectors. [ABSTRACT FROM AUTHOR]

Acetone (C 3 H 6 O) is key member of the volatile organic compound family, which can cause health as well as environmental issues. The identification and sensing of acetone gas are important in many applications such as air quality control and biomarker-based diagnosis. Here, we synthesized hollow CuO/Cu 2 O octahedrons heterostructure composite through coprecipitation and subsequent heat treatment. The sensor manifested a response of 3.52–50 ppm acetone gas at 350 °C. Besides, it showed excellent stability in a 150-day test and excellent repeatability, with a response of 4.15. Also, exhaled gas sensing was carried out using standard method to estimate the acetone concentration in breath. The high sensing capability of the sensor was ascribed to the formation of p-p heterojunctions, the hollow morphology of octahedrons, and the presence of structural defects. The hollow CuO/Cu 2 O octahedron sensor with good performance may be employed for the detection and monitoring of acetone gas in real situations. • Synthesis of hollow CuO/Cu 2 O octahedrons composite heterostructure through coprecipitation and subsequent heat treatment. • This sensor found selective and stable for acetone gas detection even at 1 ppm of concentration under humid atmosphere. • The fabricated gas sensor exhibited a response of 3.52–50 ppm acetone gas at 350 °C. • The sensor exhibits good stability, lasting for up to 150 days under high humidity conditions • Details of sensing mechanism of hollow CuO/Cu 2 O octahedrons are discussed. [ABSTRACT FROM AUTHOR]

In this study, the Bi 2 CrO 6 /CuO nanocomposite was used for the photocatalytic degradation of methylene blue (MB) under visible light. Nanocomposites with different ratios (1:1, 1:2, 2:1) were synthesized under hydrothermal conditions and investigated for MB removal. Various characterization techniques, including XRD, FT-IR, FE-SEM, BET, DRS, PL, and EDS, were employed to elucidate the physicochemical aspects of the catalysts. The 2:1 nanocomposite ratio was selected as the photocatalyst with the highest removal efficiency (85 %). Four main factors, including initial concentration, solution pH, catalyst dose, and light intensity, were studied using the response surface methodology (RSM) and the Box-Behnken model. Under optimal conditions, the MB removal efficiency reached 90.06 %. Additionally, the effect of oxidizing agents (H 2 O 2) on the enhanced removal of MB was investigated. The improved photocatalytic performance of the Bi 2 CrO 6 /CuO (2:1) nanocomposite is attributed to visible light absorption, the formation of a p-n heterostructure, efficient charge separation via the S-scheme mechanism, and increased charge carrier lifetime. Moreover, economic calculations showed that the estimated costs for the photocatalytic removal of MB from wastewater are cost-effective. [Display omitted] • Hydrothermal method is used to prepare the Bi 2 CrO 6 /CuO nanocomposite. • Structural and morphology studies confirmed the formation of heterostructures. • Loading of Bi 2 CrO 6 nanotubes over CuO nanoparticles improved the catalytic activity. • The nanocomposite BC-2:1 degraded 85% of MB under visible light. • Strong interfaces and charge separation improved the performance of Bi2CrO6/CuO nanocomposite. [ABSTRACT FROM AUTHOR]

Copper oxide (CuO) and Zinc oxide (ZnO), coating have attracted attention for their potential antiviral properties, including their ability to combat virus. This study focuses on the development and characterization of self-disinfecting surface passivation films composed of CuO and ZnO, obtained using the spin-coating technique. The research aims to develop surfaces that can actively eliminate harmful microorganisms, reducing the risk of infections, while also offering strong mechanical resistance and adhesion to withstand external factors, which is crucial for ensuring long-term effectiveness. Additionally, the microstructural properties of the elaborated films were analyzed using SEM/EDS, which stands for Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy and X-Ray diffraction analysis (XRD). The mechanical behavior was assessed through Vickers hardness and scratch resistance tests. It was found a dense and homogeneous thin films. The hardness of CuO and ZnO films were 11.14 ± 0.04 GPa, and 8.89 ± 0.04 GPa respectively. Therefore, scratching tests revealed high adhesion properties with a critical load L C1 of 1.89 ± 0.02 N and 1.04 ± 0.02 N for CuO and ZnO films respectively. Then, this study revealed that CuO and ZnO films exhibit excellent antimicrobial activity against Staphylococcus aureus ATCC 29213, as well as outstanding antiviral activity against the HSV-2 virus. [Display omitted] • Nanometric CuO and ZnO thin films show a dense and homogeneous microstructure. • CuO and ZnO coatings demonstrate high antimicrobial and antiviral properties. • Thin films exhibited good resistance to scratching indicating strong adhesion to their substrates. • CuO and ZnO films exhibit good mechanical resistance, which is essential to fully benefit from their antimicrobial and antiviral properties. [ABSTRACT FROM AUTHOR]

The core of heterogeneous catalytic systems is to design high-performance heterogeneous catalysts. In the present study, CuO-PEI-JE was synthesized via in situ precipitation of CuO on the 3D structure of PEI-JE prepared by a cross-linking method. It possessed a macro-size and 3D open-cell structure, being easily separated and having super-performance for PDS activation. Compared to PDS alone (0.0017 min−1), the CuO-PEI-JE + PDS + NaHCO 3 system increased the k obs (0.3526 min−1) by a factor of 207 with 100% phenol degradation within 20 min and 87% TOC removal at 30 min. It outperformed many other published heterogeneous persulfate systems in phenol degradation. Meanwhile, the developed system displayed a good anti-interference ability in the coexistence of anions or different water matrixes. After five successive cycles, the degradation rate still kept 100%, exhibiting the excellent reusability of CuO-PEI-JE. Furthermore, the preparation of CuO-PEI-JE had the advantages with moderate preparation conditions (60 °C) and readily available raw materials. The activation mechanism was mainly involved in the formation of active PDS and its further decomposition into ·OH ads , SO 4 · − ads , O 2 · - and 1O 2. Surface functional groups and phenol acted as electron donors for active PDS. Phenol was first degraded into hexadienedioic acid, then oxidized to propane diacid and oxalic acid, and finally mineralized into CO 2 and H 2 O. This work provides a new strategy for preparing effective heterogeneous persulfate activators and has high potential for the treatment of phenol-containing wastewater. [Display omitted] • The prepared CuO-PEI-JE activated PDS effectively and had excellent reusability. • The developed system had good anti-interference ability and low Cu2+ leaching. • OH ads , SO 4 ·− ads , O 2 ·- and 1O 2 were identified as the dominant reactive species. • Surface functional groups and phenol acted as electron donors for active PDS. • Phenol was degraded via converting to fatty acids and then to CO 2 and H 2 O. [ABSTRACT FROM AUTHOR]

In this work, the effect of substrate temperature (ST) during deposition and dopant amount of Mn (1,3,5, and 7 %) and Y(3 %), (Mn/Y), on the physical properties of copper oxide (CuO) the nanostructured film were analyzed using different diagnostic tools. The pure and (Mn, Y) co-doped CuO thin films were deposited by the spray pyrolysis method, which is effective and easy to apply for any substrate. Deposited pure and (Mn,Y) co-doped CuO nanostructured films were investigated by X-ray diffraction (XRD), UV–Vis spectroscopy, and Field emission scanning electron microscopy (FESEM) techniques to analyze the influence of ST and co-doping on the structural, morphological, and optical properties of prepared films. The FESEM is used to visualize nanostructures on the surface of the film. Also, it is observed that the surface morphology of CuO film changes from a spherical-like to a nanocloumnar-like structure with increasing substrate temperature. The XRD diffractograms confirm the monoclinic crystal structure of CuO, in polycrystalline nature for all deposited films. UV–Vis spectra suggest changing the optical absorbance and the band gap of the pure and Mn/Y co-doped CuO nanostructured films. In the first investigation of this study, the better substrate temperature was obtained as 400 °C according to results. In the second part, the effect of Y and Mn doping with different content was analyzed for the CuO film deposited at the chosen ST of 400 °C. There is no observable crystalline structure variation in the XRD pattern, but the size of nanostructure and dislocation density are varied with Mn/Y co-doping. FESEM micrographs confirm the impact of the co-doping concentration on the size, shape, and surface properties of CuO nanostructured film. In addition, the optical band gap increases with Mn doping up to 3 % of Mn content and it was determined as 2.69 eV for the sample 3Mn/Y@CuO nanostructured film. The obtained results suggest that the substrate temperature has an important impact on the physical properties of the spray deposited CuO nanostructured film, and the structural, optical, and surface properties of the CuO nanostructured films may be engineered by Mn/Y doping concentration. [ABSTRACT FROM AUTHOR]

[Display omitted] • Self-sacrificial template-directed method to prepare mesoporous CuO micro/nanoplates. • CuO plates are examined as a highly efficient photo-Fenton-like catalyst. • 100% sulfathiazole degradation and 87.3 % TOC removal under vis LED irradiation. • Excellent reusability up to the five cycles. In this study, we offer a simple self-sacrificial template-directed method to prepare mesoporous CuO micro/nanoplates by using copper hydroxide acetate (Cu 2 (OH) 3 (CH 3 COO)·H 2 O) plates as a template. The as-prepared material was structurally, morphologically, optically and texturally characterized and its excellent catalytic activity in the LED-driven photo-Fenton-like process of sulfathiazole oxidation was demonstrated. Within 90 min, 100 % sulfathiazole degradation and 87.3 % TOC removal were achieved in the presence of H 2 O 2 and visible LED irradiation. Moreover, the degradation of sulfathiazole can still reach 96.1 % after five cycles, which indicates exceptional performance of the catalyst. [ABSTRACT FROM AUTHOR]

Metal semiconductor oxides (MOSs) derived from metal-organic frameworks (MOFs) possess unique internal structure that offer great potential for development in the sensing fields. In this study, we synthesized reduced graphene oxide (rGO) doped nanocubic CuO with Cu(Ⅱ)-BTC as a sacrificial template. The rGO/CuO-10 flexible sensor exhibits 30-fold improvement in response to 10 ppm H 2 S at room temperature (RT) compared to pure CuO and theoretical detection limit down to 10 ppb. The sensor also maintains good stability when bent at different angles. The response enhancement can be owed to the composition of p-p heterostructure between rGO and CuO, the two-dimensional layered structure of rGO and the special morphology of CuO. Consequently, this study provides insights into preparation of flexible sensors based on MOFs-derived MOSs to detect H 2 S at RT. • The rGO/CuO nanocomposites are synthetized by simple hydrothermal and calcination. • RGO doped CuO nanocomposites are synthesized by using Cu(II)-BTC as a sacrificial template. • The sensor exhibits high response toward H 2 S gas at room temperature (25 ℃). • The sensor presents theoretical detection limit down to 10 ppb. • This sensor is suitable for the field of flexible wearables. [ABSTRACT FROM AUTHOR]

This research study focused on providing a solution to the problem of efficiency in the solar cell using window layer thickness. A novel Ag/WO3/CuO/Si heterojunction solar cell geometry as a function of WO3 window layer thickness via cost-effective hydrothermal and spin coating approaches has been demonstrated. The structural, morphological, and optical characteristics were systematically studied, indicating a direct correlation with the fabricated solace cells’ efficiency. In detail, a decrease in the WO3 layer thickness from 150 to 50 nm resulted in the average transmission increment from 58 to 75%; this, in turn, allowed higher power conversion efficiency enhancement from 0.063 to 1.387%. Specifically, short circuit currents of 0.307 and 6.206 mA/cm2 and open circuit voltages of 0.259 and 0.779 V were attained for the aforementioned layers’ thickness, respectively. [ABSTRACT FROM AUTHOR]

• A new photocatalyst InGaZn 0.3 Cu 0.7 O 4 with CuO to decompose tetracycline efficiently. • The Cu2+ doping in InGaZnO 4 significantly improves the light absorption properties. • The layered structure of InGaZn 0.3 Cu 0.7 O 4 is conducive to the enhancement of photodegradation performance. Herein, we reported a new photocatalyst InGaZn 0.3 Cu 0.7 O 4 with co-catalyst CuO for the photo-oxidation of tetracycline. Copper doping in InGaZnO 4 significantly reduced the bandgap and enhances the absorption of visible light. The photocatalytic performance was further enhanced by making a composite with CuO. In the photo-oxidation reaction of tetracycline, the kinetic constant of the optimal composite is 0.0111 min−1, which is 3.0 and 10.1 times higher than those of InGaZnO 4 and InGaCuO 4 , respectively. The photocatalytic mechanism suggested that photogenerated holes play the most important role in the oxidation of tetracycline. [ABSTRACT FROM AUTHOR]

In this paper, polyoxometalates (POMs) electron acceptors were introduced into a classical p-type gas sensitive ceramic-copper oxide (CuO). Then, we investigated the effect of phosphomolybdic acid (PMA) on the sensing performance of CuO gas sensors. The results show that by introducing PMA, the response of CuO gas sensor to 100 ppm ethanol gas can be effectively improved to 2.78. This promotion may be due to the electron trapping effect of PMA, which promotes the carrier migration and inhibits its recombination. Simultaneously, the response and recovery time of the sensor is only 5 s and 4 s. Other gas sensing parameters of the sensors were also comprehensively investigated. The mechanism analysis shows that PMA, as an electron-transport mediator, can trap electrons in the conduction band of CuO, generate shallow electron traps, and effectively inhibit the recombination of electrons and holes in CuO, thereby enhancing gas sensing performance. This work provides a new idea for the advance of CuO-based gas sensors with enhanced sensing sensitivity using polyoxometalates as electron acceptors. [Display omitted] • First demonstration of the influence of POMs on gas sensing performance of CuO. • The decoration of POMs enhanced the ethanol gas-sensing performance of CuO. • The CuO/1%PMA sensor exhibit an enhanced response of 2.78 to 100 ppm ethanol gas. • The sensor exhibits very rapid response/recovery time of only 5/4 s. • Other gas sensitive parameters were comprehensively explored. [ABSTRACT FROM AUTHOR]