Copper Oxide Nanopowders Research Articles

Physiochemical and electrical activities of nano copper oxides synthesised via hydrothermal method utilising natural reduction agents for solar cell application

Abstract The aim of this study is to explore the potential compatibility of copper oxide nano-powders synthesised via hydrothermal method for solar cell applications by triggering a reaction between copper acetate and various reducing agents derived from natural resources, including Arabic gum, molasses, starch, and vinegar. X-ray diffraction analysis revealed the crystalline phases of the synthesised materials, indicating the successful synthesis of copper oxide material, which was confirmed by identifying patterns that matched specific copper oxide phases. Fourier transform infrared spectroscopy was employed to analyse the molecular vibrations and chemical compounds present in the reducing agents. The reducing properties of the selected materials and their capacity to convert copper acetate into copper oxide were validated. Field-emission microscopy and transmission electron microscopy analyses of the synthesised copper oxide nanoparticles (NPs) revealed variations in particle size and morphology. These variations were dependent on the particular reducing agent utilised during synthesis. Moreover, the carrier concentration, mobility, and resistivity were evaluated as the electrical properties of the spin-coated copper oxide thin films. Hall effect analysis determined that the choice of reducing agent significantly influenced the carrier concentration (n) and mobility (µ) of the films. Remarkably, nano copper oxide films synthesised using starch exhibited irregular spherical grains with porous surfaces. Starch-synthesised samples showed the highest conductivity of n = 1.2 × 1019 cm−3 when compared with those synthesised with other reducing agents. This suggests that the porous surfaces in the starch-synthesised films may have contributed to their enhanced conductivity compared to films synthesised with alternative reducing agents. In summary, the findings emphasised the influence of the reducing agent on the size, morphology, and electrical conductivity of the copper oxide NPs.

Antifungal and Coagulation Properties of a Copper (I) Oxide Nanopowder Produced by Out-of-Phase Pulsed Sonoelectrochemistry.

Copper (I) oxide (cuprite) is a material widely used nowadays, and its versatility is further amplified when it is brought to the nanometric size. Among the possible applications of this nanomaterial, one of the most interesting is that in the medical field. This paper presents a cuprite nanopowder study with the aim of employing it in medical applications. With regards to the environmental context, the synthesis used is related to green chemistry since the technique (out-of-phase pulsed electrochemistry) uses few chemical products via electricity consumption and soft conditions of temperature and pressure. After different physico-chemical characterizations, the nanopowder was tested on the Candida albicans to determine its fungicide activity and on human blood to estimate its hemocompatibility. The results show that 2 mg of this nanopowder diluted in 30 µL Sabouraud broth was able to react with Candida albicans. The hemocompatibility tests indicate that for 25 to 100 µg/mL of nanopowder in an aqueous medium, the powder was not toxic for human blood (no hemolysis nor platelet aggregation) but promoted blood coagulation. It appears, therefore, as a potential candidate for the functionalization of matrices for medical applications (wound dressing or operating field, for example).

Exploring the Colors of Copper-Containing Pigments, Copper (II) Oxide and Malachite, and Their Origins in Ceramic Glazes

The colors of copper-containing pigments, copper (II) oxide and malachite, and their origins in ceramic glazes were systematically examined over a wide firing temperature range using a suite of analytical and spectroscopy techniques including SEM, UV-Vis FORS, XRD, FTIR, and EPR to gain new insight into the structural and chemical transformations of the glaze during firing. The two colorants investigated were black copper (II) oxide (CuO) nanopowder and blue-green basic copper carbonate, or malachite (Cu2CO3(OH)2), both of which produce a final light blue color following firing. Additionally, silicon carbide (SiC) was used to locally reduce CuO to simulate firing glazes in a reductive environment and produce a final red color. At lower temperatures, malachite was found to decompose to form CuO at 550 °C, elucidating the reason that two different copper colorants could be used interchangeably to form the same “Robin’s Egg Blue” color. At 850 °C, a glaze sintering process occurred, resulting in the distribution of Cu2+ in a square planar geometry and an observed blue color. This structural change occurred at temperatures lower than the glaze’s melting point, indicating that complete vitrification of the glaze is not required for glaze coloration. Conversely, the reduction in Cu2+ to Cu+ through the addition of SiC did not occur until the glaze was fired above the melting temperature (1000 °C), signifying that high temperatures are required for the redox reaction to occur. This study sheds light on intermediate colorant-glaze interactions that are beneficial for understanding and predicting glaze coloring upon exposure to varying temperatures, and the results from this study can be applied to better-controlled glaze production for artists and a deeper appreciation of ceramic glaze chemistry and aesthetics.

Synthesis, physico-chemical characterizations and antibacterial properties of copper oxide (I) nanopowders elaborated by out-of-phase pulsed sonoelectrochemistry

Nanopowders of copper (I) oxide (Cu2O, cuprite) were synthesized by out-of-phase pulsed sonoelectrochemical method and characterized by several physico-chemical techniques (X-ray diffraction, transmission electronic miscroscopy, energy-dispersive x-ray spectroscopy, centrifugal liquid sedimentation, zeta potentials and specific area measurements). The same analyses were done on commercial cuprite and copper nanopowders for comparison. Once the chemical nature and morphology of the three materials have been determined, bactericidal assays were performed on methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) in Trypto-Casein-Soy medium. The results show that sonoelectrochemical Cu2O nanopowders are good antibacterial material as compared to the two commercial nanopowders while using a synthesis method that is inexpensive and adaptable to the industrial scale.

Combined Effect of Phosphonium Ionic Liquid and Copper Oxide Nanopowder as Additives to the Bio-based Lubricant During Tribological Analysis

Combined Effect of Phosphonium Ionic Liquid and Copper Oxide Nanopowder as Additives to the Bio-based Lubricant During Tribological Analysis

RETRACTED ARTICLE: Nanoparticle effect of heat conduction mechanism during solidification of PCM

In this modeling investigation, freezing of NEPCM inside a chamber with triangular cold cylinder has been scrutinized. With mixing copper oxide nano-powders and H2O, new material has been generated. To include the impact of nano-powder shape, empirical correlations were utilized. For simulation of such transient conduction mechanism, finite element approach was applied with considering grid adaption. Amplitude of top wall and shape coefficient were two active factors and simulations were demonstrated their effects. Examination of accuracy of code shows nice agreement. Adding nano-powders enhances the conduction and style of powders can affect the freezing process. The minimum time for full freezing is 197.0352 s which can be achieved when A = 0.3 and m = 5.7. Augment of shape factor leads to decrement of time by 8.36%. With rise of A, freezing time declines by 11.78% because PCM volume decreases inside the chamber.

Design development and thermal performance assessment of latent heat storage of a solar stove unit involving NEPCM

In current article, various sizes of copper oxide nano-powders on solidification phenomena through a tank with one sinusoidal adiabatic wall have been investigated. The shape of cold wall was circular and inside the tank filled with water. For enhancing the conduction mode, nanoparticles were dispersed in the PCM. FEM was utilized for simulation in which the region near the solid front has finer grid to capture the temperature gradient easier. The amplitude of adiabatic wall has been considered as another variable in simulations. Outcomes in view of isotherms and profiles were established. With growth of dp from 30 to 40 nm, the solidification time changes from 576.23 to 459.16 s. In addition, augmenting dp from 40 to 50 nm makes the required time to rise about 49.24%. As amplitude of adiabatic wall augments, the required time augments about 22.45%

Increasing the freshwater productivity of a solar still loaded with CuO nanofluids using vibration motion and cover cooling techniques

The performance of a single-slope solar still system has been improved with the addition of copper oxide (CuO) nanopowder in water as nanofluid and thermoelectric glass cover cooling combination. The use of vibration further enhances the performance of distillate water as a result of the accelerated heat transfer. In this study, CuO nanofluids loaded the solar still system at volume concentrations of 0.5%, 1%, and 1.5%. The design, fabrication, and testing of the single still were conducted under the local weather conditions of Alexandria, which is located in the northwest of Egypt. The proposed solar still had a base area of 1 m2 and fitted with four coiled springs, a DC motor, and a photovoltaic (PV) solar panel. The vibration generator was a three-phased, with a 1-HP power motor (220 V, 50 Hz, and 1380 rpm maximum speed) fixed to a compact disk with a small punch for adding masses to generate the un-mass balance forces. The power source for the DC motor was a 250-W PV. The daily output of fresh water during the experimental period was empirically measured under the same climate conditions, and the results were compared with those of a conventional solar still. The daily rates of freshwater productivity were investigated in two cases: (a) under vibration without cover cooling and (b) under vibration with cover cooling at the three given nanofluid volume concentrations. Based on the results, the highest daily freshwater productivity attained with the vibration and cover cooling (at the 1.5% nanofluid volume concentration) 7.13, 4.97, and 3.36 kg/day, and the daily efficiency increases by 54%, 43% and 36% compared to the conventional case at the water depths of 10, 20, and 30 mm, respectively, with a maximum estimated cost of 0.027653$/L/m2.

Single-step fabrication of superhydrophobic urchin-like copper oxide nanopowders: Effect of structure-directing agents

The use of superhydrophobic metal oxide nanoparticles has been considered for the construction of self-cleaning, anti-corrosion, anti-icing, anti-fogging, and oil/water separation surfaces, but the low chemical and thermal stabilities of applied organic modifiers restrict their wide applications. In this study, the superhydrophobic copper oxide nanoparticles with the hierarchical urchin, flower and spherical-like architectures were fabricated via a simple and facile single-step hydrothermal method without any post chemical modification. Taguchi experimental design was used to evaluate and optimize the synthesis parameters such as structure-directing agent concentration and its type, synthesis temperature, and the molar ratio of the complexing agent to the initial copper (II) ions. The wettability characteristics of synthesized samples were assessed based on the chemical composition of powders and their morphological structures. The scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) analyses were used to characterize the resultant samples. The wettability properties of samples were determined by measuring the water contact angle (WCA) and contact angle hysteresis (CAH). The results confirmed that the synthesized sample under the optimum condition had an excellent superhydrophobic property with a WCA of 158.4⁰±2⁰ and CAH of 1.5⁰. The surface wettability evaluations also revealed that the morphology and surface free energy of the powders could be controlled simultaneously by alterations of type and concentration of the structure-directing agent, in order to enhance the anti-wetteing characteristics.

Investigation of the Quenching Rate Effect on the Ferromagnetic Properties of CuO Nanoparticles

We studied the effect of pressure in a plasma-chemical reactor on the magnetic properties of copper oxide nanoparticles. Plasma-chemical synthesis of copper oxide nanopowders was carried out using an oxygen plasma of an arc discharge at pressures of 40 Pa and 200 Pa. Transmission electron microscopy showed that the obtained samples were made up of highly agglomerated particles with average particle sizes of 31 nm and 27 nm, respectively. X-ray diffraction showed the presence of a single crystalline phase of CuO. Despite the insignificant difference in the average sizes, the nanoparticles exhibited radically different magnetic behavior. Using a vibrating superconducting quantum interference device magnetometer, it was shown that the magnetic properties of nanoparticles obtained at 40 Pa were close to the bulk material and exhibited weak ferromagnetism. The nanoparticles obtained at 200 Pa demonstrated a significant deviation from the properties of the bulk material, showed magnetic hardness, and shifts in the hysteresis loops.

Correlations between the Characteristics of the Initial and Final Materials of Copper Nanopowder

Using the example of copper oxide nanopowders, the correlation between the morphology and particle size of the initial and final materials is investigated by means of X-ray fluorescence, X-ray phase analysis, electron microscopy, and thermogravimetric analysis. From 10% salt solutions, an oxygen-containing copper sediment which was a mixture of copper hydroxonitrate Cu2(OH)3NO3 and copper oxide CuO was synthesized, from which powders with various morphologies were formed by various types of treatment. The reactions occurring during thermal decomposition of the obtained sediment were established, as well as the scheme of reducing Cu2(OH)3NO3 to metal copper. The phase composition, morphology, and particle size of the deposited material and metal product were studied. A scheme of formation of metal copper nanoparticles from copper hydroxonitrate is proposed.

Effects of CuO nanoparticles as phase change material on chemical, thermal and mechanical properties of asphalt binder and mixture

Copper oxide nanopowders (Nano-CuO) as phase change material (PCM), Styrene-Butadiene-Styrene (SBS), and carbon nanotubes (CNTs) as a conductive material, were added separately and together in five combination designs to hot mix asphalt (HMA). Controlling the thermal energy transfer was achieved by using Nano-CuO. FTIR analysis illustrated that PCM eliminated the destructive bonds that caused short and long term aging in asphalt binder. From the DSR test results, it was deduced that the modified asphalt binders met the fatigue resistance limit. It was determined that the thermal energy storage (TES) in PCM-modified asphalt binders increased and, also glass transition temperature Tg significantly improved, melting peak temperature Tpm were higher than the pure asphalt binder, and crystallization peak temperature Tpc decreased by 7 °C. According to BBR test results, creep stiffness St and m-value for the modified asphalt binders adhere to the permissible limits at −6 °C. Nano-CuO-modified asphalt binders significantly increased the specific heat capacity Cp of asphalt binders and decreased the temperature and moisture susceptibility. Overall, the combination, including all the three additives, had the most acceptable properties.

In Vitro Aerosol Exposure to Nanomaterials: From Laboratory to Environmental Field Toxicity Testing.

Exposure to nanomaterials (NMs) is inevitable, requiring robust toxicological assessment to understand potential environmental and human health effects. NMs are favored in many applications because of their small size; however, this allows them to easily aerosolize and, subsequently, expose humans via inhalation. Toxicological assessment of NMs by conventional methods in submerged cell culture is not a relevant way to assess inhalation toxicity of NMs because of particle interference with bioassays and changes in particokinetics when dispersed in medium. Therefore, an in vitro aerosol exposure chamber (AEC) was custom designed and used for direct deposition of NMs from aerosols in the environment to the air-liquid interface of lung cells. Human epithelial lung cell line, A549, was used to assess the toxicity of copper, nickel, and zinc oxide nanopowders aerosolized by acoustic agitation in laboratory study. Post optimization, the AEC was used in the field to expose the A549 cells to NM aerosols generated from firing a hand gun and rifle. Toxicity was assessed using nondestructive assays for cell viability and inflammatory response, comparing the biologic effect to the delivered mass dose measured by inductively coupled plasma-mass spectrometry. The nanopowder exposure to submerged and ALI cells resulted in dose-dependent toxicity. In the field, weapon exhaust from the M4 reduced cell viability greater than the M9, while the M9 stimulated inflammatory cytokine release of IL-8. This study highlights the use of a portable chamber with the capability to assess toxicity of NM aerosols exposed to air-liquid interface in vitro lung cell culture.

Comparative analysis of the morphology of doped zinc and copper oxide nanopowders

Nano-oxides attracted the attention of the reserchers due to their numerous applications. From this point of view, the development of new synthesis methods has become equally important for industry. The use of solar energy can become one of the ecological methods of obtaining nano-powders. Our paper presents the comparison of the morphology of nanopowders of Al-doped zinc oxide and Mn-doped copper oxide, obtained by physical vapour deposition using solar energy (SPVD), at different pressure and solar flux. The morphological characterization of doped oxide nanopowders synthesized by SPVD was performed by scanning electron microscopy.

Pre-stressing aluminum nanoparticles as a strategy to enhance reactivity of nanothermite composites

Aluminum (Al) fuel particles are used in a variety of energetic formulations yet harvesting their full chemical potential energy and increasing their energy release rate upon ignition have been a challenge and are key motivators to advancing energy generation technologies. One approach to improving combustion performance is to alter the mechanical properties of the Al particle by inducing an elevated stress state through prestressing. This study examines the combustion performance of prestressed nanoscale aluminum (nAl) particles that were annealed to temperatures ranging from 200 to 400 °C and quenched at slow (exponential) and faster (linear) cooling rates. Powder X-ray diffraction measurements show that prestressing nAl particles at 300 °C increases the strain by an order of magnitude. Constant volume combustion cell tests on nAl combined with copper oxide nanopowder (nAl + CuO) revealed higher peak pressures and pressurization rates for prestressed nAl + CuO composites compared to their untreated counterpart. High speed emission spectroscopy was employed to deduce condensed phase temperatures from the reaction confined within the combustion cell. Burn time measurements, obtained by integrating the emission spectra, were observed to correlate inversely with generated pressure. High heating rate (∼5 × 105 K/s) in-situ TEM results augment the combustion cell results. The results imply that prestressing mechanically alters the nanoparticles which subsequently accelerate the release of aluminum core through outward diffusion. This results in the rapid loss of nanostructure which was observed at the nanoscale through in-situ electron microscopy. The released aluminum thus reacts rapidly with the oxidizer in the condensed phase resulting in a faster and more violent reaction. Improved performance of prestressed nAl coupled with the simplicity of processing provides a low cost and scalable approach to improving metal fuel particle combustion.

Research of Some Technological and Physico-Mechanical Characteristics of Composite Materials Obtained by Modification of Epoxy Binder with Copper and Copper oxide Nanopowders

Results of research of the influence of nanomodification of epoxy bonding element on its technological and physical mechanical properties. It is shown that implementation of bonding nanodispersed copper oxide and copper leads to a significant reduction of strength quality of the compound. Thus if there was minimum tried amount of copper powder 0,01%, damaging tension during stretching was 2MPa, for the control sample without copper it was 57 MPa.

Biologically active nanomaterials in production and storage of arable crops

Obtaining high-quality environmentally safe crop products, which would ensure the necessary level of human health, is the main task of biological farming. Nowadays, the leading role is given to long-term ecological (adaptive) plant breeding, designed to promote the most complete use of bioclimatic resources and mobilise the internal biological potential of plants. The realisation of the potential of varieties and hybrids is largely determined by the organisation of seed production, the varietal and sowing qualities of seeds. An equally important component of the solution to the problem is biopreparations, making possible a fuller realisation of the genetic potential of various varieties and hybrids of vegetable crops, yield increase (30-40%), biosynthesis of biologically active polymers (25-45%) and plant protection after a single treatment of seeds. The paper presents the effect of various types of nanomaterials, such as iron, cobalt and copper, copper oxide and cobalt oxide nanopowders, on the carrot variety 'Nantskaya 4' and potatoes of the 'Latona' variety. The influence of nanomaterials on the morphological and physiological parameters of plants, yield, the crop structure and chemical composition of carrots and potatoes, as well as the content of vitamins C and PP in potato tubers, has been studied. The safety of vegetable production has been established due to lowering the chemical load during the vegetative period, since the preparations have a prolonged action, are used in low concentrations and can replace traditional micro fertilisers, growth stimulants, and pesticides. Based on the research, the introduction of biologically active nanomaterials into intensive technology for growing these crops is recommended. Using the biopreparations developed by the authors, the consumer receives significant savings in the process of growing major vegetable crops: an increase in yield and quality, which will lead to some increase in the total number of products and profitability of production.

Synthesis of Copper Oxide Nanopowder by Microwave Method

Copper oxide nanopowder was successfully synthesized by microwave method. Copper acetate and sodium hydroxide were used as the starting precursors. The microwave power was set to 800 Watt for 2-6 min and fine black nanopowder was obtained. The nanopowder was milled and dried at 80 °C for 12 h. The structure was identified by X-ray diffractometer (XRD). A monoclinic single phase of CuO nanopowder structure was obtained without calcination steps. The morphology was investigated by scanning electron microscope (FESEM). The particle was irregular in shape and agglomerated. The chemical composition was determined by energy dispersive X-ray spectrometer (EDXS). The chemical compositions showed the characteristic X-ray energy of copper (Kα=8.048 keV) and oxygen (Kα=0.525 keV), respectively. The functional group was investigated by fourier transform infrared spectrometer (FTIR). The functional groups of the vibration Cu-O bending showed the wavenumber at 491-615 cm-1.

Electrochemical properties of hollow copper (II) oxide nanopowders prepared by salt-assisted spray drying process applying nanoscale Kirkendall diffusion

The synthesis of hollow CuO nanopowders by a salt-assisted spray drying process applying nanoscale Kirkendall diffusion is introduced. The electrochemical properties of the hollow CuO nanopowders for lithium-ion storage are also investigated. The first step of post-treatment of the spray-dried powders under a reducing atmosphere forms spherical and hollow NaCl powders embedded with Cu nanocrystals. Further post-treatment of the Cu–NaCl composite powders under an air atmosphere forms the spherical and hollow NaCl powders embedded with the hollow CuO nanopowders. Oxidation of the Cu nanocrystals under an air atmosphere produces hollow CuO nanopowders by nanoscale Kirkendall diffusion. The spherical and hollow CuO–NaCl composite powder transforms into ultrafine hollow CuO nanopowders by complete washing with distilled water to remove NaCl. The initial discharge and charge capacities of the hollow CuO nanopowders for lithium-ion storage at a current density of 1 A g−1 are 1077 and 781 mA h g−1, respectively. The reversible discharge capacity of the hollow CuO nanopowders for the 700th cycle is 803 mA h g−1.

Preperation and Characterization Study of Phase Change Materials for Thermal Energy Storage Applications

Thermal Energy Storage using phase change materials (PCM) has become an interesting area of energy research because of its high energy storage density, isothermal nature of storage process and small volume changes. In the present work paraffin wax (PW) and Palmitic acids(PA) are chosen as phase change materials and mixed in different proportions(40-60% PW-PA, 50-50% PW-PA and 60-40% PW-PA) to prepare eutectic PCMs. And also paraffin is combined with Copper oxide nano powder to prepare composite PCM. Differential Scanning Calorimetric (DSC) Tests have been conducted to find the latent heat capacity of the above combination of PCMs. The results showed that 40-60%PW-PA eutectic mixture is effective in increasing the latent heat of fusion compared to the other combinations.