Copper Oxide Nanostructures Research Articles

Viscosity sensing by low power optical self phase modulation in two dimensional copper oxide nanostructures

Viscosity is an inherent property of fluids and thus an important parameter in a variety of application. However current viscosity measurement methods necessitate direct contact with the liquid sample, which is normally undesirable. Herein we have reported viscosity sensing by low power optical self phase modulation (SSPM) in 2D CuO layered nanostructuresin glucose solution. The SSPM ring pattern formation time is found to be varied almost linearly with viscosity of the glucose solution. The third-order nonlinear susceptibility (χ3) of the nanostructure has been evaluated and is found to be 5.76 × 10−6 esu.The viscosity of an unknown glucose solution has been evaluated by this technique which matched extremely well with the theoretical value. The high n2 value of the nanostructures indicates its usability in opto-electronic applications like all optical switching, etc.

Green Synthesis and Characterization of Copper Oxide Nanostructures from Chromolaena odorata Leaves Aqueous Extract for Potential Biomedical Applications: An Eco-friendly Approach

Green Synthesis and Characterization of Copper Oxide Nanostructures from Chromolaena odorata Leaves Aqueous Extract for Potential Biomedical Applications: An Eco-friendly Approach

CuO-TiO2 nanostructures prepared by chemical and electrochemical methods as photo electrode for hydrogen production

In present study, copper (II) oxide (CuO) nanostructures were separately synthesized via chemical and electrochemical methods. CuO were coated with chemically synthesized titanium dioxide (TiO2). Morphological and structural properties of CuO and TiO2 coated CuO (CuO-TiO2) materials were examined via field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). FESEM images showed that nanowire like CuO formed at both chemical and electrochemical techniques. TiO2 nanoparticles were homogenously distributed all over CuO surfaces. XRD pattern revealed CuO has monoclinic crystal structure with metallic Cu. Moreover, rutile TiO2 crystallized in the tetragonal crystal structure. Electrochemical impedance spectroscopy (EIS) and potentiodynamic (PD) polarization measurements were utilized to study electro catalytic performance of the materials towards hydrogen evolution reaction (HER). The values of both energy consumption, and energy efficiency were determined as 329.43 kJ mol−1 and 86.0% at −50 mA cm−2 current density for HER on electrochemically synthesized CuO-TiO2 at 25 °C.

Copper oxide nanoleaves covered with loose nickel oxide nanoparticles for sensitive and selective non-enzymatic nitrite sensors

In this work, we developed a new method for preparing copper oxide (CuO) nanostructures, designed and prepared a CuONiO modified fluorine-doped SnO2 transparent conductive glass (FTO) electrode for electrochemical sensor to effectively detect the nitrite. The leaf-shaped CuO nanostructures grow uniformly on the FTO electrode, resulting in the increased contact area and reduced transfer resistance. The NiO nanoparticles effectively dispersed in the gaps between the leaves can further improve the electron transfer and reduce the diffusion resistance. The electrochemical results demonstrated that the prepared electrode exhibited high sensitivity (7.2 mA mM−1 cm−2), broad linear range (0.001–1.8 mM) and low detection limit (0.013 μM). Moreover, the prepared sensor also reflected good reproducibility, stability and anti-interference in the detection of actual samples, which provides a good application prospect for metal oxides used in water quality and environmental monitoring.

Determination of the Influence of Various Factors on the Character of Surface Functionalization of Copper(I) and Copper(II) Oxide Nanosensors with Phenylboronic Acid Derivatives.

In this work, we attempt to determine the influence of the oxidation state of copper [Cu(I) vs Cu(II)], the nature of the interface (solid/aqueous vs solid/air), the incubation time, and the structure of N-substituted phenylboronic acids (PBAs) functionalizing the surface of copper oxide nanostructures (NSs) on the mode of adsorption. For this purpose, 4-[(N-anilino)(phosphono)-S-methyl]phenylboronic acid (1-PBA) and its two analogues (2-PBA and bis{1-PBA}) and the copper oxide NSs were synthesized in a surfactant-/ion-free solution via a synthetic route that allows controlling the size and morphology of NSs. The NSs were characterized by scanning electron microscopy, ultraviolet–visible spectroscopy, Raman spectroscopy, and X-ray diffraction, which confirmed the formation of spherical Cu2O nanoparticles (Cu2ONPs) with a size of 1.5 μm to 600 nm crystallized in a cubic cuprite structure and leaf-like CuO nanostructures (CuONSs) with dimensions of 80–180 nm in width and 400–700 nm in length and crystallized in a monoclinic structure. PBA analogues were deposited on the surface of the copper oxide NSs, and adsorption was investigated using surface-enhanced Raman spectroscopy (SERS). The changes in the orientation of the molecule relative to the substrate surface caused by the abovementioned factors were described, and the signal enhancement on the copper oxide NSs was determined. This is the first study using vibrational spectroscopy for these compounds.

New Construction of Functionalized CuO/Al2O3 Nanocomposite-Based Polymeric Sensor for Potentiometric Estimation of Naltrexone Hydrochloride in Commercial Formulations.

Electrically conductive polymeric nanocomposites with nanoparticles are adaptable types of nanomaterials that are prospective for various applications. The extraordinary features of copper oxide (CuO) and aluminium oxide (Al2O3) nanostructures, encourages extensive studies to prospect these metal oxide nanocomposites as potential electroactive materials in sensing and biosensing applications. This study suggested a new CuO/Al2O3 nanocomposite-based polymeric coated wire membrane sensor for estimating naltrexone hydrochloride (NTX) in commercial formulations. Naltrexone hydrochloride and sodium tetraphenylborate (Na-TPB) were incorporated in the presence of polymeric polyvinyl chloride (PVC) and solvent mediator o-nitrophenyloctyl ether (o-NPOE) to form naltrexone tetraphenylborate (NTX-TPB) as an electroactive material. The modified sensor using NTX-TPB-CuO/Al2O3 nanocomposite displayed high selectivity and sensitivity for the discrimination and quantification of NTX with a linearity range 1.0 × 10−9–1.0 × 10−2 mol L−1 and a regression equation EmV = (58.25 ± 0.3) log [NTX] + 754.25. Contrarily, the unmodified coated wire sensor of NTX-TPB exhibited a Nernstian response at 1.0 × 10−5–1.0 × 10−2 mol L−1 and a regression equation EmV = (52.1 ± 0.2) log [NTX] + 406.6. The suggested modified potentiometric system was validated with respect to various criteria using the methodology recommended guidelines.

A Promising Three-Step Heat Treatment Process for Preparing CuO Films for Photocatalytic Hydrogen Evolution from Water.

Copper (II) oxide (CuO) nanostructures were prepared on fluorine-doped tin oxide (FTO) using a three-step heat treatment process in a sol–gel dip-coating method. The precursor used for the dip-coating process was prepared using copper acetate, propan-2-ol, diethanolamine, and polyethylene glycol 400. Dip-coated films in layers of 2, 4, 6, 8, and 10 were prepared by drying each layer at 110 and 250 °C for 10 and 5 min, respectively, followed by calcination at 550 °C for 1 h. The films were applied toward photocatalytic hydrogen evolution from water. The X-ray diffraction (XRD) pattern of the films confirmed the tenorite phase of pure CuO. Raman spectroscopy revealed the 1Ag and 2Bg phonon modes of CuO, confirming the high purity of the films produced. The CuO films absorb significant photons in the visible spectrum due to their low optical band gap of 1.25–1.33 eV. The highest photocurrent of −2.0 mA/cm2 at 0.45 V vs reversible hydrogen electrode (RHE) was recorded for CuO films consisting of six layers under 1 sun illumination. A more porous surface, low charge transfer resistance, and high double-layer capacitance at the CuO/electrolyte interface observed for the films consisting of six layers contributed to the high photocurrent density attained by the films. CuO films consisting of six layers prepared using the conventional two-step heat treatment process for comparative purposes yielded 65.0% less photocurrent at 0.45 V vs RHE compared to similar films fabricated via the three-step heating method. The photocurrent response of the CuO nanostructures prepared using the three-step heat treatment process is promising and can be employed for making CuO for photovoltaic and optoelectronic applications.

Comparative Studies on Synthetic Strategies for the Growth of CuO Nanostructures and Their Significant Impact on Supercapacitive Performance

AbstractThe copper oxide (CuO) nanostructures are synthesized by various simple and cost‐effective chemical methods. The morphology of metal oxide nanostructures depends on the synthetic strategy. The electrochemical behavior primarily depends on the morphology of the electrode. The significant impact of synthetic strategy on the structural, morphological, and subsequently on the supercapacitive performance of CuO nanostructures is studied. The chemical bath deposition (CBD) leads to well defined growth of 1D nanostructures, while the intermittent growth process (successive ionic layer adsorption and reaction, SILAR) leads to nanoparticulate morphology. CBD grown CuO nanorods have shown comparatively higher capacitance (207 F g−1) than CuO nanoparticles (147 F g−1) at current density of 2 A g−1.

Room Temperature Surface Oxidation by Alkalization of Binder Free CuO Nanostructured Electrode for Enhanced Supercapacitive Performance

AbstractThe copper oxide (CuO) nanostructures are synthesized via facile oxidation of Cu foil in an aqueous KOH solution at room temperature. A precleaned Cu foil immersed in a 0.1 M aqueous KOH solution for different time periods (36–72 h) systematically converts its surface into nanochained to rice husk morphology and then agglomerated dense nanoclusters. The impact of immersion time on the morphology and consequently supercapacitor performance is studied. The CuO nanostructure synthesized at an immersion time of 60 h shows a maximum specific capacitance of 302 Fg–1 at a scan rate of 2 mV s−1. The capacitance retention reaches up to 87% after 2000 cycles.

Plasma-enhanced thermal growth of copper oxide nanostructures on anode of glow discharge setup

Plasma-enhanced growth of copper oxide nanostructures is widely explored in science and manufacturing, since it provides the flexibility, productivity, and cost-effectiveness necessary to meet the growing demands of customers. However, in the field of growth of metal oxide nanostructures, thermal methods still prevail in plasma methods in spite of long production time up to ten hours. Radiofrequency and microwave plasma sources were applied to grow CuO nanostructures, which are of high interest in various branches of industry, and allowed obtaining a large variety of the nanostructures, and nanowires in particular. At that, high price of the equipment limits the implementation of the results and urges to find cheaper plasma-enhanced method of growth. For this purpose, a common glow discharge plasma setup was engaged to grow the nanostructures in an oxygen atmosphere on surfaces of samples installed on the anode of the electric circuit designed to sustain the glow discharge. An additional heater was mounted under the anode. The proposed combination allowed conducting the growth process under conditions of the delivery of the necessary heat flux and removal the excessive ion flux that can destroy the growing nanostructures because of sputtering. In the first set of experiments, the additional heater was not used, and the observed nanostructures were presented by grains (2D) of about 370 nm in diameter and 80 nm in thickness. This structure is supposedly formed because of action of the internal stresses in the oxide layer. After turning on the heater, the nanowires (1D) were the only nanostructures observed in the experiment, and since no nanowires were found in a case of heating the anode without plasma ignition, one can consider the plasma as a factor determining the nanowire growth.

Electric-Field-Induced Phase Change in Copper Oxide Nanostructures.

Transition-metal oxides such as cupric and cuprous oxides are strongly correlated materials made of earth-abundant chemical elements displaying energy band gaps of around 1.2 and 2.1 eV. The ability to design nanostructures of cupric and cuprous oxide semiconductors with in situ phase change and morphological transition will benefit several applications including photovoltaic energy conversion and photoelectrochemical water splitting. Here, we have developed a physicochemical route to synthesize copper oxide nanostructures, enabling the phase change of cupric oxide into cuprous oxide using an electric field of 105 V/m in deionized water via a new synthetic design protocol called electric-field-assisted pulsed laser ablation in liquids (EFA-PLAL). The morphology of the nanostructures can also be tuned from a sphere of ∼20 nm to an elongated leaf of ∼3 μm by controlling the intensity of the applied electric field. Futuristically, the materials chemistry occurring during the EFA-PLAL synthesis protocol developed here can be leveraged to design various strongly correlated nanomaterials and heterostructures of other 3d transition-metal oxides.

Nanostructured Mesoporous Zinc-Incorporated Copper Oxide (NMZI-CuO): An Efficient and Reusable Nanocatalyst for the Oxidant-Free Synthesis of Quinoxalines through a Tandem Oxidation Process

A nanostructured mesoporous zinc-incorporated copper oxide with different Cu/Zn molar ratios was prepared through a facile hydrothermal template-free route. Textural properties of prepared materials were studied with various techniques such as TEM, BET, XRD, FTIR, and XPS. The prepared mesoporous zinc-incorporated copper oxide was then successfully applied as a heterogeneous catalyst for the synthesis of quinoxaline derivatives from 1,2-diamines and α -hydroxy ketones through a tandem oxidation process (TOP) without any oxidant. Using this method all desired products were obtained with good to excellent yields in relatively short times under solvent-free conditions. The applied catalyst was simply isolated and reused several times without any detectable loss of catalytic activity.

Formation of Copper Oxide Nanotextures on Porous Calcium Carbonate Templates for Water Treatment.

The necessity of providing clean water sources increases the demand to develop catalytic systems for water treatment. Good pollutants adsorbers are a key ingredient, and CuO is one of the candidate materials for this task. Among the different approaches for CuO synthesis, precipitation out of aqueous solutions is a leading candidate due to the facile synthesis, high yield, sustainability, and the reported shape control by adjustment of the counter anions. We harness this effect to investigate the formation of copper oxide-based 3D structures. Specifically, the counter anion (chloride, nitrate, and acetate) affects the formation of copper-based hydroxides and the final structure following their conversion into copper oxide nanostructures over porous templates. The formation of a 3D structure is obtained when copper chloride or nitrate reacts with a Sorites scaffold (marine-based calcium carbonate template) without external hydroxide addition. The transformation into copper oxides occurs after calcination or reduction of the obtained Cu2(OH)3X (X = Cl− or NO3−) while preserving the porous morphology. Finally, the formed Sorites@CuO structure is examined for water treatment to remove heavy metal cations and degrade organic contaminant molecules.

Photocatalytic studies of copper oxide nanostructures for the degradation of methylene blue under visible light

As a well-known global fact, the presence of toxic, non-biodegradable and harmful organic pollutants in soils, wastewater, and atmosphere has become an indisputable significant environmental problem. The present study reports the photocatalytic properties of the cubic-shaped Cu/Cu2O/CuO and bud-shaped CuO nanoparticles for methylene blue (MB) removal from the synthetic dye solution. Nanocrystalline copper oxide particles are synthesized by a simple solvothermal method followed by an annealing process at 400 °C in an open atmosphere. The crystalline structure and morphology of the nanoparticles are characterized by X-ray diffraction and field emission-scanning electron microscopy. The optical band gap energies of the prepared powders are estimated using the UV–vis spectrometer. Interestingly, cubic shaped Cu/Cu2O/CuO nanoparticles shows a photo-degradation efficiency of about 78% after 120 mins whereas bud-shaped CuO shows 61% in the presence of H2O2. Further, Cu/Cu2O/CuO nanoparticles show good recyclability of up to three cycles. The excellent photocatalytic performance and reusability properties of Cu/Cu2O/CuO heterojunctions also synergistically lowers the electron–hole recombination rate, promotes the utilization of light and photo-generation of charge carriers. All these combined effects result in the enhanced photocatalytic degradation and mineralization of the MB dye.

Effect of Ultraviolet and Solar Radiation on Photocatalytic Dye (Black-E and Congo Red) Degradation Using Copper Oxide Nanostructure Particles

Effect of Ultraviolet and Solar Radiation on Photocatalytic Dye (Black-E and Congo Red) Degradation Using Copper Oxide Nanostructure Particles

Pitch‐Black Nanostructured Copper Oxide as an Alternative to Carbon Black for Autonomous Environments

Nanostructured Copper Oxide In article number 2100049, a novel nanostructured copper oxide as an alternative to carbon black is demonstrated by Songtao Wu, Gunugunuri Reddy, Debasish Banerjee. This nanostructured copper oxide has specific prevalence of crystal facets, creating visually pitch-black material which yet selectively reflects near infra-red LiDAR detectable wavelength. This work opens new opportunities to use dark colored objects in future autonomous environment.

Influence of Ni doping on the morphological, structural, optical and electrical properties of CuO thin films deposited via a spray pyrolysis

Nanostructured copper oxide (CuO) and Nickel (Ni)-doped CuO thin films with different concentrations of Ni ranging from 2 to 8 at.% were synthesized onto a plain glass substrate at the substrate temperature, 350 °C by a thermal spray pyrolysis technique. Field emission scanning electron microscopy (FESEM) analysis of CuO and Ni-doped CuO thin films detected the closely spaced rock-like nanostructures, evenly distributed on the film surfaces. The average particle sizes of CuO and Ni-doped CuO thin films were calculated from the FESEM and found between 260 and 63 nm. Energy-dispersive X-ray analysis revealed that CuO and Ni-doped CuO thin films were stoichiometric and typically comprised of Cu, O, and Ni. X-ray diffraction analysis showed the monoclinic structure of the films with the most preferred orientation plane ( 1 ‾ 11) along with the (111), ( 2 ‾ 02) and (02 2 ‾ ) crystalline planes. The maximum crystallite size was found at about 81 nm for 6 at% Ni-doped CuO thin film. CuO film showed an optical transmittance of about 33% in the visible-NIR region. Ni-doping enhanced the absorbing nature of CuO thin films in the vis-NIR region of light. With the rise of Ni content in CuO thin films, the optical bandgap gradually increased from 2.28 to 2.78 eV. Resistivity raised from 9.28 × 10 3 to 49.01 × 10 3 Ω-cm with the increase of the amount of Ni. • The FESEM micrographs show that the thin film surface of the CuO and nickel (Ni)-doped CuO thin films comprises irregularly shaped nanoparticles that aggregate to form the columnar surface's morphology. • As the Ni increased in the precursor solution for the preparation of Ni-doped CuO thin films, EDX analysis of the prepared films showed an increase in Ni's mass and atomic percentage. • The films' monoclinic structure with the preferred orientation along with the ( 1 ‾ 11) crystalline plane is shown in the X-ray diffraction analysis. • Ni-doping enhanced the absorbing nature of CuO thin films in the vis-NIR region of light. • The optical band gap and electrical resistivity gradually increased with an increase in the CuO thin film's Ni content.

Fabrication of copper oxide nanostructures for visible-light photodetector

Cu(II)O has emerged as a promising material for numerous applications including photodetectors due to its narrow bandgap (1.5 eV), environmentally innocuous nature, low cost, and ease of fabrication. Herein, the optoelectrical investigation of polycrystalline cupric oxide (Cu(II)O) based photodetectors has been studied. The Cu(II)O film has been fabricated over FTO substrate which has been assembled into a sandwich structured photodetector device to record the current–voltage (I-V) and current–time (I-t) characteristics. The fabricated device demonstrates responsivity of 60 µA/W and detectivity of 1.9 × 108 Jones. The proposed process is facile, low cost and even suitable for flexible photodetectors. Furthermore, the Cu(II)O films exhibit promising photon sensing characteristics in visible and near UV light illumination and can be explored for various other applications in photodetection and photovoltaic studies.

Deep eutectic solvent mediated nanostructured copper oxide as a positive electrode material for hybrid supercapacitor device

Metal oxides have received significant attention for various applications over the last few decades due to their better structural, morphological, and electrochemical properties. Herein, a green approach is introduced for the synthesis of nanostructured CuO using a choline chloride urea (CCU)-based deep eutectic solvent (DES) method. The effects of varying reaction times upon the surface morphological and electrochemical properties of the CuO are examined. In particular, the CuO sample obtained at 12 h of reaction time is shown to exhibit a porous nanograin-like surface morphology with a grain size of less than 20 nm and an excellent specific capacity (Cs) of 176 mAh g−1 at a scan rate of 5 mV s−1. Further, the practicability of the CuO-based electrode is demonstrated by the fabrication of a CuO//activated carbon (AC) hybrid supercapacitor device. The CuO//AC shows a noteworthy electrochemical performance, with a Cs of 82 mAh g−1, specific energy of 35.86 Wh kg−1, a specific power of 2017 W kg−1, and a long-term stability of 98% after 2000 cycles.

Photocatalytic effect of CuO nanoparticles flower-like 3D nanostructures under visible light irradiation with the degradation of methylene blue (MB) dye for environmental application

The present research work focuses on preparing 3D transition metal doped copper oxide nanostructures through sonication method and to investigate the effect of doping different transition metal into copper oxide (CuO) on the basic properties of CuO nanoparticles and, to study the photocatalytic behaviour of the doped CuO samples. The morphological studies performed with the help of SEM revealed the formation of flower like CuO 3D nanostructures for all the doped samples. The slight shift in the position of peaks in the x-ray diffraction (XRD) pattern confirms that doping has been successfully done into CuO. Also, the sharp diffraction peaks suggest the polycrystalline nature of the sample with monoclinic structure. The UV–vis absorption analysis reveals a bandgap of 2.26, 2.12 and 2.15 eV for the CuO samples doped with nickel, zinc, and iron respectively via Tauc plot. The photocatalytic performance of the samples tested through the degradation of methylene blue (MB) dye suggests that samples doped with Zn shows better degradation. Thus, it is evident that the morphology and the optical properties of the CuO can be tailored by doping transition metal into it.