Commercial CuO Powder Research Articles

Characterization of YBa2Cu4O8 superconductor prepared by using YBa2Cu3O7-x and CuO via solid state reaction technique with heating under ordinary oxygen pressure

The aim and objective of this study is to investigate the material synthesis and superconducting properties of YBa2Cu4O8 (Y-124) synthesized from YBa2Cu3O7-x (Y-123) and CuO powders. A commercial Y-123 and CuO powders were used to synthesize polycrystalline Y-124 employing the conventional solid state reaction method with heating at 1 atm oxygen pressure. Sodium nitrate was used as catalytic enhancer during the chemical reaction. The samples were subjected to twice sintering at 815 °C for 24 h with intermittent grinding. Analysis of the x-ray diffraction (XRD) data showed that Y-124 phase is dominance (81.1 wt%) in the samples with the presence of Y-123, and CuO as secondary phases. The thermogravimetric curve shows a small oxygen loss at ∼ 400 °C and rapid oxygen loss above ∼ 850 °C. Scanning electron microscope (SEM) images revealed that the samples had irregular grain shapes ranging in size from a few micrometers to fractions of a micrometer. The four-point-probe method was used to measure superconducting transition temperature (Tc). The samples exhibited a dual superconducting transition with the onset Tc of around 77 K and 87 K, respectively. This is consistent with the co-existence of superconducting phase Y-124 and Y-123. This two-level Tc characteristic of the sample gave potential application in multiples industries, including electronics, transportation, and data storage and processing. This study demonstrates how efficient and optimal conditions can be used to produce the Y-124 phase.

Cu3N-derived hydrophobic porous CuO hollow nanospheres for NO2 detection at room temperature

Good humidity resistance property are crucial for gas sensors to achieve high-performance sensing characteristics at room temperature. In this work, porous raspberry-like CuO hollow nanospheres were produced by calcining the Cu3N nanosphere precursors through a solid-gas displacement reaction involving the Kirkendall effect. The raspberry-like CuO hollow nanospheres had spherelike microstructure with nanoparticle-built rough surface, thereby showing a hydrophobic characteristic with a high static contact angle (143.0°). The CuO hollow nanospheres exhibited a high response of 26.2–300 ppb NO2 even under a high relative humidity of 80% at room temperature, 18.7 times greater than the commercial CuO powder. In addition, the response/recovery times of CuO hollow nanospheres were shorter than those of the CuO powder, with 1.9-fold/3.2-fold improvements in response/recovery kinetic coefficients. CuO hollow nanospheres also displayed good NO2 selectivity and cycling repeatability. The improved NO2 sensing characteristics of the CuO hollow nanospheres were primarily attributable to their increased specific surface area and porosity, increased response/recovery kinetics, and hydrophobic surface.

CuO-ZnO submicroflakes with nanolayered Al2O3 coatings as high performance anode materials in lithium-ion batteries

Transition metal oxides are said to have the ability to enhance the gravimetric capacity of lithium-ion batteries by two or three times that of current state-of-the-art graphite anodes. Recent reports have demonstrated that the combined utilization of structural architecture and surface modification is an attractive strategy to improve lithium storage capability. In this study, novel CuO-ZnO@Al2O3 submicroflakes were prepared by magnetron sputtering deposition of Cu-Zn alloy films on a removable sacrificial substrate, followed by a facile thermal oxidation treatment and Al2O3 coating procedure by particle atomic layer deposition. They combine the advantages of CuO-ZnO submicroflakes, such as high lithium storage capability and fast lithium ion transportation, and Al2O3 nano-coating with effective protection of the electrode interface during cycling. When utilized as anode materials for LIBs, the CuO-ZnO@Al2O3 submicroflakes exhibit superior specific capacity, enhanced cycling stability, and outstanding rate capability compared with pristine CuO-ZnO submicroflakes, commercial CuO and ZnO powders. The CuO-ZnO@Al2O3 submicroflakes electrodes deliver a high reversible capacity of 814 mAh g−1 at a current density of 50 mA g−1, and still maintain a moderate capacity of 447 mAh g−1 at a high current density of 1000 mA g−1. Pairing with a commercial LiFePO4 cathode, full cell shows high capacity retention and stable cycling performance, suggesting the feasibility of the CuO-ZnO@Al2O3 submicroflakes in practical energy storage applications. In addition, our findings also provide a clear proof-of-concept of the surface coating technique, which might be applied widely to other materials and devices where nano-coating produces desirable properties.

Co3O4 Nanopetals Grown on the Porous CuO Network for the Photocatalytic Degradation.

Designing a novel photocatalytic composite for the efficient degradation of organic dyes remains a serious challenge. Herein, the multi-layered Co3O4@NP-CuO photocatalyst with unique features, i.e., the self-supporting, hierarchical porous network as well as the construction of heterojunction between Co3O4 and CuO, are synthesized by dealloying-electrodeposition and subsequent thermal treatment techniques. It is found that the interwoven ultrathin Co3O4 nanopetals evenly grow on the nanoporous CuO network (Co3O4@NP-CuO). The three-dimensional (3D) hierarchical porous structure for the catalyst provides more surface area to act as active sites and facilitates the absorption of visible light in the photodegradation reaction. Compared with the commercial CuO and Co3O4 powders, the newly designed Co3O4@NP-CuO composite exhibits superior photodegradation performance for RhB. The enhanced performance is mainly due to the construction of heterojunction of Co3O4/CuO, greatly promoting the efficient carrier separation for photocatalysis. Furthermore, the possible photocatalytic mechanism is analyzed in detail. This work provides a promising strategy for the fabrication of a new controllable heterojunction to improve photocatalytic activity.

Facile Nonenzymatic Glucose Electrode Composed of Commercial CuO Powder and Ionic Liquid Binder

Commercially available micro-sized CuO powder was dispersed in the mixture of ethanol and protonated betaine bis((trifluoromethyl)sulfonyl)amide ([Hbet][TFSA]), a hydrophobic amide-type protic ionic liquid (IL), to prepare a composite paste for the modification of screen-printed carbon electrode (SPCE) via spin-coating. The fabricated SPCE\CuO−IL composite-based electrode showed a comparable activity as that of the nanonized metal-oxide based electrodes towards the electrochemical oxidation of glucose in alkaline solutions. Hydrodynamic chronoamperometry tests performed at +0.55 V showed a linear dynamic response of the electrode over the concentration range of 1 μM–2.8 mM with a sensor-sensitivity of 0.16 μA μM−1 in 0.1 M NaOH. The data also showed a linear dynamic response over the concentration range of 1 μM–4.6 mM with a sensor-sensitivity of 0.10 μA μM−1 in 0.1 M NaOH with 0.1 M NaCl, indicating that the major interferant Cl− had negligible effects on glucose detection . Ascorbic acid (AA) (in the physiological level) and ethanol also did not interfere with the detection. Detection of glucose in real samples showed the recovery ratios higher than 95 %. This study has clearly demonstrated that commercial CuO powder without nanostructure can provide sufficient reactivity to the electrocatalytic oxidation of glucose by using IL as the organic binder. Facile preparation of the micro-sized metal oxide-modified electrodes can be accordingly pursued.

Metal–organic framework-derived Cu2O–CuO octahedrons for sensitive and selective detection of ppb-level NO2 at room temperature

Cu2O–CuO heterojunction octahedrons were fabricated by the thermal decomposition of Cu-based metal–organic framework (MOF) precursors. The adsorbed oxygen species (O2-) content was visibly increased by constructing such kind of p–p heterojunctions. Compared with commercial CuO powder, this kind of Cu2O–CuO octahedrons exhibited much better sensing properties to NO2. At room temperature (RT, 25 °C), the Cu2O–CuO octahedrons showed a higher response, reaching 8.25–500 ppb NO2, which was 2.88 times higher than that of CuO powder. Besides good NO2 stability and selectivity, a low detection concentration down to 10 ppb was also revealed at RT for the Cu2O–CuO octahedrons. From our perspective, the enhanced NO2 sensing properties of the Cu2O–CuO octahedrons can be mainly attributed to the formation of Cu2O–CuO p–p heterojunctions, facilitating the adsorption of more O2- species to participate in the sensing reaction. The results here demonstrated that MOF-derived Cu2O–CuO octahedrons with a p–p heterojunction construction had a good potential for sensitive and selective detection of ppb-level NO2 at RT.

Electrochemically derived CuO nanorod from copper-based metal-organic framework for non-enzymatic detection of glucose

In this work, we fabricated a novel enzyme-free glucose sensor based on CuO nanorod, which was electrochemically derived from the copper-based metal-organic framework, Cu3(BTC)2 (BTC: benzene tricarboxylate). Repeated potential cycling successfully oxidized Cu3(BTC)2 to CuO, leaving residual carboxylate on the catalyst surface. The oxidation process was carefully investigated by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform IR, and scanning electron microscopy. Cyclic voltammetry and chronoamperometry studies of the electrochemical oxidation of glucose on the CuO nanorod revealed excellent electrocatalytic performance with high sensitivity of 1523.5 μA mM−1 cm−2, linear response up to 1.25 mM, and detection limit of 1 μM. Compared with commercial CuO powder, the CuO nanorod showed much higher sensitivity because of its large surface area (60.2 m2 g−1). Moreover, it exhibited good selectivity to glucose over potential interfering compounds. These results suggest the potential application of the Cu3(BTC)2-derived CuO nanorod as a non-enzymatic glucose sensor.

Starch-based polyurethane/CuO nanocomposite foam: Antibacterial effects for infection control

In the present study, a new method for the synthesis of the open cell flexible polyurethane foams (PUFs) was developed by using starch powder and the modification of closed cell foam formulation. Starch is the second largest polymeric carbohydrate as a macromolecule on this planet with a large number of glucose units. Copper oxide nanoparticles (CuO NPs) were synthesized by thermal degradation method at different temperatures of 400, 600 and 800 °C as antimicrobial agents. The antimicrobial activity of CuO NPs and commercial CuO powder against the main causes of hospital infections were tested. CuO600 was the most effective antimicrobial agent and enhanced polymer matrix tensile strength with starch powder as new polyurethane foams (PUFs) cell opener with high tensile strength. The effects of parameters on tensile strength were optimized using response surface methodology (RSM). CuO NPs and PUF had optimal conditions and were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Foam synthesized at the optimal conditions had an open cell structure with high tensile strength and efficient antimicrobial activity that made them suitable to be used as an antimicrobial hospital mattress to control hospital infections.

Shuttle-Like CuO as High-Performance Anode Materials for Lithium Ion Batteries

Shuttle-like CuO has been synthesized by treating commercial Cu(OH)2 powder at room temperature for an appropriate time. As anode material of lithium-ion batteries, shuttle-like CuO exhibits high specific capacity, high stability, and good rate performance, superior to commercial CuO powder. The shuttle-like CuO exhibited a high specific capacitance of 456.8 mAh g-1 at a current density of 100 mAg-1 and maintained a good stability in 50 cycles, suggesting that it can be a promising candidate for lithium-ion batteries. The high specific capacitance and remarkable rate capability are promising for applications in lithium-ion batteries with both high energy and power densities.

Hollow CuO microspheres with open nanoholes: Fabrication and photocatalytic properties

A kind of novel hollow CuO microspheres with open nanoholes was fabricated via a SiO2 template-assisted synthesis process under hydrothermal conditions in the present work. Sodium silicate acted as an alkaline medium as well as SiO2 precursor. Copper sulphate and glucose were used as copper source and reducing agent, respectively. The as-synthesized products consisted of Cu2O/SiO2 mixture, which was transformed completely into CuO/SiO2 after calcinations at 600 °C, and then SiO2 could be removed by NaOH etching. Eventually, a kind of hollow CuO microspheres with open nanoholes was attained. Results showed such microspheres were composed of numerous small CuO crystalline grains, and the productions of hollow inner structures and open nanoholes were from the imprints of SiO2 nanoparticle removal. Meanwhile, the effect of the amount of sodium silicate in the reaction was investigated, suggesting such CuO microspheres could be fabricated only if an enough amount was used. In addition, we also propose the possible formation mechanism of such nanostructures. These CuO microspheres exhibited a better photocatalytic activity on the degradation of methyl orange (MO) than commercial CuO powders (∼200 nm) under the identical conditions.

Synthesis of Novel Hollow Copper Oxide Micro-Flowers Assembled by Nanoparticles and Their Improved Catalytic Performances for the Synthesis of Organosilane

In this work, novel sisal-like hollow CuO micro-flowers were synthesized via a facile solvothermal reaction followed by calcination. The flower-like shells of hollow CuO are constructed by irregular petals interweaving each other, which are composed of aggregated nanoparticles with sizes of ca. 18[Formula: see text]nm. It was found that the flower-like morphology of the as-synthesized CuO products can be controlled via finely tuning the solvothermal reaction time. When used as catalysts for the synthesis of organosilane, the obtained hollow CuO micro-flowers exhibit better catalytic performances than the commercial CuO powders. Superior catalytic performances are due to the hollow and flower-like structures of the as-synthesized CuO products, which can promote the synthetic reaction for the organosilane, that is, the gas–solid contacting reaction occurred among the reaction gas, solid silicon powders and CuO catalysts. Our work will be helpful to design and develop the novel Cu-based nanocatalysts for the synthesis of organosilane.

Fabrication of snowflake-like CuO nanostructure via electrodeposition method and its properties

CuO films with snowflake-like nanostructures on indium tin oxide-coated glass substrates were successfully synthesized by electrodeposition method. Detailed characterization of the synthesized nanomaterials was performed utilizing X-ray diffraction, field emission scanning electron microscopy and UV–Vis absorption spectra to study their crystalline phase, morphology and optical property. Morphological controllable fabrication can be realized by adjusting preparation parameters. The results showed a blue-shift in the optical band gap (Eg = 3.38 eV) due to quantum confinement effect. Good photocatalytic activity was exhibited and photo-degradation rate to methylene blue can reach 91.2 % compared to commercial CuO powder. A growth mechanism for the formation of CuO nanostructure was also explained.

Facile preparation of a monodispersed CuO yolk-shelled structure with enhanced photochemical performance

Tailored design of photocatalysts with complicated hollow structures is of great importance for promoting environmental remediation. Herein, a monodispersed CuO yolk-shelled structure is synthesized for the first time by simple calcination treatment of a pre-synthesized Cu–EG (ethylene glycol) complex with yolk-shelled structure using a simple, environmentally friendly and glycerol-mediated solvothermal method. Ostwald ripening is the main formation mechanism for the yolk-shelled structure. Such CuO yolk-shelled structures show excellent photocatalytic activity, which is 3.65 times faster than that of the commercial CuO powders and is one of the highest reported photocatalytic activities to date in the CuO nanomaterials for the degradation of rhodamine B (RhB) under visible light irradiation. Such a preferable photocatalytic activity is mainly attributed to the unique yolk-shelled structure, which can enable higher multiple light reflections and scattering between the outer spherical shell and the interior core compared with commercial CuO powders, to provide a more efficient way to enhance light-harvesting efficiency.

Facile synthesis of graphene-like copper oxide nanofilms with enhanced electrochemical and photocatalytic properties in energy and environmental applications.

Novel graphene-like CuO nanofilms are grown on a copper foam substrate by in situ anodization for multifunctional applications as supercapacitor electrodes and photocatalysts for the degradation of dye pollutants. The as-prepared CuO consists of interconnected, highly crystalline, conductive CuO nanosheets with hierarchical open mesopores and a large surface area. The CuO nanofilms supported on a copper foam are employed as freestanding, binder-free electrodes for supercapacitors, which exhibit wonderful electrochemical performance with a large specific capacitance (919 F g(-1) at 1 A g(-1)), an excellent cycling stability (7% capacitance loss after 5000 cycles), and a good rate capability (748 F g(-1) at 30 A g(-1)). The porous CuO nanofilms also demonstrate excellent photocatalytic activities for degradation of methylene blue, with a degradation rate 99% much higher than 54% of the commercial CuO powders after 60 min. This excellent energy storage and photocatalytic performance of the graphene-like CuO nanofilms can open a new avenue for large-scale applications in energy and environmental fields.

Novel porous CuO microrods: synthesis, characterization, and their photocatalysis property

Porous copper oxide microrods have been synthesized via calcining copper glycinate monohydrate microrod precursor which was prepared in mild conditions without any template or additive. Several techniques, such as X-ray diffraction, field emission scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller (BET) N2 adsorption–desorption analyses, were used to characterize the structure and morphology of the products. Scanning electron microscopy (SEM) analyses show that the precursor consists of a large quantity of uniform rod-like micro/nanostructures with typical lengths in the range of 25–40µm and diameters in the range of 0.1–0.35µm. The microrod-like precursors transformed into porous microrod products after calcination at 450°C in flow air for 2h. The BET surface area of the porous CuO microrods was calculated to be 8.5m²g−1. In addition, the obtained porous CuO microrods were used as catalysts to photodegrade rhodamine B (RhB), methyl orange, methylene blue, eosin B, and p-nitrophenol. Compared with commercial CuO powders, the as-prepared porous CuO microrods exhibit superior properties on photocatalytic decomposition of RhB due to their porous hierarchical structures.

Microwave-hydrothermal synthesis of CuO nanorods and their catalytic applications in sodium humate synthesis and RhB degradation

CuO nanorods have been prepared through a facile microwave-hydrothermal method with the aid of polyethylene glycol 400, ethylene glycol and urea. The X-ray diffraction and transmission electron microscopy results showed that the prepared CuO nanocrystalline had a rod-like shape with diameters of 15–20nm and the average length of 80nm. Compared with commercial CuO powder, the CuO nanorods showed an enhanced catalytic activity for the synthesis of sodium humate and the degradation of Rhodamine B. The yield of sodium humate catalyzed by CuO nanorods was 75.78%, which was higher than that of the commercial CuO powder (52.8%). In addition, the CuO nanorods showed a relatively faster degradation rate of RhB. The CuO nanorods prepared by this facile method demonstrated their potential applications in the field of catalysis.

Au nanoparticles decorated CuO nanowire arrays with enhanced photocatalytic properties

Au nanoparticles decorated CuO nanowire arrays have been successfully prepared and investigated their photocatalytic activity. It has been found that Au–CuO nanowire arrays exhibit enhanced photocatalytic performance with 92.7% decomposition of rhodamine B (RhB) after 8h reaction under UV exposure, which is much higher than that of CuO nanowire arrays (65%) and commercial CuO powders (44%).

Size effect and enhanced photocatalytic activity of CuO sheet-like nanostructures prepared by a room temperature solution phase chemical method

Size effect and photocatalytic activity of CuO sheet-like nanostructures, which were synthesized by a facile solution phase chemical method with ethanol and water mixture as solvent, have been investigated by UV–vis absorption spectrum and photocatalytic degradation of pollutant rhodamine B (RhB). UV–vis absorption spectrum indicated that the band gap energy was about 2.31eV for the as-prepared CuO nanostructures. The result indicates that the band gap energy of the CuO sheet-like nanostructures is much larger than value of bulk CuO crystals, showing that the CuO sheet-like nanostructures exhibit a strong quantum size confinement effect. The photocatalytic activity indicates that the as-synthesized CuO sheet-like nanostructures show an enhanced photocatalytic activity with 96.7% degradation of RhB after 9h reaction under UV light irradiation, which was much higher than that of commercial CuO powders (39.6%).

Sponge-like mesoporous CuO ribbon clusters as high-performance anode material for lithium-ion batteries

Hemispherical CuO clusters assembled by mesoporous nanocrystal ribbons are directly grown on Ni foam. As anode material of lithium-ion batteries, CuO ribbon clusters exhibit high specific capacity, high stability, and good rate performance, superior to commercial CuO powder. At 0.2C, after 50 cycles, the discharge capacities are still 3 times that of commercial CuO, sustaining 81% discharge capacity of the 2nd cycle. At 0.5–4C, the discharge capacity is 206–572mAhg−1. The improved electrochemical performances result from the unique nano-assembled structure.

Porous CuO superstructure: Precursor-mediated fabrication, gas sensing and photocatalytic properties

A facile route was developed for the large-scale preparation of porous CuO superstructures based on a hydrothermal route with subsequent calcination. The CuO superstructures show “box-like” shape and are composed of microplatelets with high porosity resulting from the thermal decomposition of the precursor. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform spectroscopy (FT-IR) and Brunauer–Emmett–Teller N2 adsorption–desorption analyses were employed to characterize the microstructure, size and crystalline phase of the porous cupric oxide product. The porous CuO superstructures with pore size of about 20nm have a surface area of 18.2m2/g. The gas-sensing measurements of the porous CuO superstructures demonstrate that the obtained CuO product exhibits higher sensing response to ethanol, propanol and acetone than commercial CuO powder. In addition, the enhanced photocatalytic activity of the porous CuO superstructures was also demonstrated with the photocatalytic degradation of methylene blue as a probe reaction. It is believed that the enhanced gas-sensing and catalytic properties are originated from their unique openly porous microstructure, which is highly beneficial to the reagent diffusion and mass transportation.