CuO Nanoneedles Research Articles

Exploring the potential of CuO nanoneedles and CNT/PVC nanocomposites in medium voltage cable technology

Exploring the potential of CuO nanoneedles and CNT/PVC nanocomposites in medium voltage cable technology

Binary-amplifying electrochemiluminescence sensor for sensitive assay of catechol and luteolin based on HKUST-1 derived CuO nanoneedles as a novel luminophore

Herein, a highly novel and effective electrochemiluminescence (ECL) sensor based on metal-organic framework (MOF, HKUST-1) derived CuO nanoneedles (HKUST-1 derived CuO NNs), gold nanoparticles (AuNPs) and TiO2 was developed for ultrasensitive detection of catechol and luteolin. The HKUST-1 derived CuO NNs were employed as luminophore for the first time, which were successfully fabricated by using HKUST-1 as precursor. The results revealed that the HKUST-1 derived CuO NNs exhibit excellent ECL activity ascribed to its abundant active site and the high specific surface area, thus obviously promoting the separation and transfer of charge and further improving the current density of ECL sensor. To binary-amplify the signal of the ECL sensor, the AuNPs and TiO2 nano-materials with good biocompatibility, great electron transport efficiency and high catalytic activity were used as co-reaction accelerators in the ECL process. Dependent on the above brilliant strategy, the proposed ECL sensor achieved wide linear ranges from 3 × 10−9 – 1 × 10−4 M for catechol and 1 × 10−8 – 2 × 10−4 M for luteolin, with the detection limits of 1.5 × 10−9 M for catechol and 5.3 × 10−9 M for luteolin, respectively. Furthermore, the ECL sensor exhibited outstanding selectivity, repeatability, stability and obtained great feedback on determination of catechol and luteolin in actual samples. The method not only filled a gap in the ECL application of MOF-derived materials but also provided a novel sight for design other highly efficient luminescent materials.

Wettability contrast on the surface of CuO nanostructures for highly efficient fog harvesting

Fog collection can provide a sustainable and efficient method for solving the shortage of water resources. In this article, CuO nanostructures were designed and synthesized on the Cu mesh by a one-step oxidation method and used to collect water from fog. Their morphology and surface wettability are characterized through scanning electron microscopy and dynamic contact angle measuring device, while the process of fog collection is investigated by a high-speed camera. The fog collection efficiency depends on the microstructure of the sample surface, which could be well controlled by adjusting the reaction temperature. Compared with CuO nanoneedles and CuO nanowire clusters, CuO nanosheets promote the rapid falling of liquid droplets, improving the fog harvesting efficiency, which can achieve 3168 mg/cm2 within 120 s. CuO nanosheets have ultra-low adhesion due to high roughness and high air restraint ability, accelerating the transport of water droplets and reducing the re-evaporation of water droplets.

Fabrication and characterization of CuO nano-needles from thermal decomposition of Cu(II) metal complex: Fluorometric detection of antibiotics, antioxidant, and antimicrobial activities

In the present study, CuO NPs and CuO nano-needles were synthesized using thermal decomposition of Cu(II) complex derived from 2-(4-(trifluoromethoxy)phenylimino)methyl)-6-methoxyphenol (TMPM6MOP) and characterized by UV–vis DRS, PL, FTIR, XRD, and SEM. The monoclinic crystalline nature of the CuO NPs and CuO needles was illustrated by the XRD. The average size of the CuO NPs (30 nm) and CuO needles (diameter 10 nm, length 250 nm) were estimated from XRD and SEM. The prepared CuO needles were used as a fluorescent sensor for the selective and sensitive detection of ciprofloxacin (Cipro) among various antibiotics at diverse pH (4.0–9.0) conditions and the optimized pH = 5.0. The response of Cipro using the CuO needles was linear over the range from 10 to 100 µM L–1. This sensor showed the lowest limit of detection of 0.21 nM and was much lower than the other antibiotic sensors. In addition, the sensor is highly sensitive, selective, and durable in the presence of a range of potentially interfering fluorometric active compounds due to the large surface area and positive surface charge of the CuO needles. Moreover, antimicrobial activities and antioxidant activities were investigated to evaluate the biological potential of the CuO NPs and CuO needles.

In-situ fabrication of superhydrophobic surface on copper with excellent anti-icing and anti-corrosion properties

The accumulation of ice on electrical construction works not only leads to the reduced efficiency of power supply and heat exchangers, but also increases the energy losses and even brings about serious disasters. Therefore, it is essential to reduce or eliminate the issue of ice accumulation on metal constructions. Nowadays, superhydrophobic surfaces have received lots of attentions for their outstanding hydrophobicity. In this study, Cu(OH)2 nano grass was firstly in-situ constructed on copper surface via simple anodization, then superhydrophobic CuO nano needles were obtained after the dehydration of Cu(OH)2 and modification with fluoro-alkyl silanes. The results showed that when the anodic oxidation temperature was 20 °C and the current density was 2 mA·cm−2, nano-needle-like multistage micro-nano structures can be obtained. The as-prepared superhydrophobic surface showed the water contact angle as large as 162° and sliding angle lower to 4°. Additionally, the as-prepared superhydrophobic surface displayed outstanding anti-icing property, delaying icing substantially even under − 10 °C environment regardless of droplet volume and type. Moreover, it also revealed good anti-corrosion property with a corrosion current density of 2.2 × 10−8 Ω·cm2 and the corrosion resistance of 1.55 × 106 Ω·cm2 which is about three order of magnitudes than that of bare copper. We prospect that this easily prepared surface can provide a solution of anti-icing and anti-corrosion for electrical construction works and large-scale metals.

Electroplating CuO nanoneedle arrays on Ni foam as superior 3D scaffold for dendrite-free and stable Li metal anode

Undesirable dendrite growth and infinite volume expansion are the major barriers to the potential application for next-generation safe Li metal batteries. To solve these problems, we herein report electroplating CuO nanoneedle arrays on Ni foam (NCNF) as 3D porous framework for Li metal batteries. The influence of different morphologies of CuO on guiding Li plating/stripping behavior has been investigated. The homogenous deposition of Li can be attributed to the interspace between the CuO nanoneedles, which is remarkably superior over granular CuO on Ni foam (GCNF) at high areal capacity. The hierarchical skeleton can not only decrease local current inhomogeneity but also alleviate the volume change of Li. The NCNF electrode delivers a higher Coulombic efficiency of Li deposition comparing with the bare Ni foam and GCNF. Furthermore, enhanced cycling stability with small overpotential can be achieved in symmetric cells. In a Li/LiFePO4 full cell, the excellent cycling performance also proves the superiority of NCNF@Li composite electrode.

Corrosion assisted the formation of unique structure transition metal oxides/carbon nanofibers with fast and high lithium storage

In this work, a facile and universal synthetic strategy is proposed to synthesize carbon nanofibers/ transition metal oxide composites with a three-dimensional cross-linked structure. The character of its morphology is the carbon nanofiber framework, based on which transition metal oxide nanoparticles and nanosheets (nanoparticles, nanoneedles) can be compounded inside and outside the nanofiber, respectively. The synthesis of this special morphology is achieved by electrospinning, heat treatment, and corrosion. By using this method, a series of hybrid materials including Co3O4/C nanofibers @ Co3O4 nanosheets (Co3O4/CFs @ Co3O4), ZnO/C nanofibers @ ZnO nanoparticles (ZnO/CFs @ ZnO), and CuO/C nanofibers @ CuO nanoneedles (CuO/CFs @ CuO) can be successfully synthesized. The capacity of Co3O4/CFs @ Co3O4 can reach 842.4 mAh g−1 after 150 cycles, and ZnO/CFs @ ZnO and CuO/CFs @ CuO also show well cycle stability and high specific capacity as 650 mAh g−1 and 544 mAh g−1 after 600 cycles at 1 A g−1. This work can inspire the research of carbon nanofibers framework composite transition metal oxide nanostructure materials for outstanding lithium storage.

Condensation heat transfer of CO[formula omitted] on Cu based hierarchical and nanostructured surfaces

Phase-change processes such as condensation are efficient means of heat transfer. However, condensation is also an energy-intensive process and extensive research is conducted to increase the heat transfer efficiency. Increasing the effective heat transfer area in terms of surface structures on macro or microscale is one such technique of heat transfer enhancement. In this work, we have studied micro- and nanostructured surfaces for their potentials in increasing heat transfer during condensation of CO2. Three Cu-based surfaces on which CuO nanoneedles have been grown, have been investigated. We hypothesize three competing mechanisms govern the overall heat transfer on structured surfaces: (1) increased heat transfer area, (2) lower thermal conductivity of oxides, and (3) condensate flooding of the structures. Our study has shown that in some cases, the effect of these mechanisms can be neutralized. More importantly, the results show that superior heat transfer can be achieved by optimizing the surface structure. The best of the structured surfaces resulted in a heat transfer coefficient 66% higher than that of the unstructured surface.

Pushing the Limits of Rapid Anodic Growth of CuO/Cu(OH)2Nanoneedles on Cu for the Methanol Oxidation Reaction: Anodization pH Is the Game Changer

We recently reported the fastest anodization method (just 80 s) of all for accessing a denser array of Cu(OH)2–CuO nanoneedles on a Cu foil substrate by applying a constant potential of 0.864 V vs ...

Nanostructured Anodic Copper Oxides as Catalysts in Electrochemical and Photoelectrochemical Reactions

Recently, nanostructured copper oxides formed via anodizing have been intensively researched due to their potential catalytic applications in emerging issues. The anodic Cu2O and CuO nanowires or nanoneedles are attractive photo- and electrocatalysts since they show wide array of desired electronic and morphological features, such as highly-developed surface area. In CO2 electrochemical reduction reaction (CO2RR) copper and copper-based nanostructures indicate unique adsorption properties to crucial reaction intermediates. Furthermore, anodized copper-based materials enable formation of C2+ hydrocarbons and alcohols with enhanced selectivity. Moreover, anodic copper oxides provide outstanding turnover frequencies in electrochemical methanol oxidation at lowered overpotentials. Therefore, they can be considered as precious metals electrodes substituents in direct methanol fuel cells. Additionally, due to the presence of Cu(III)/Cu(II) redox couple, these materials find application as electrodes for non-enzymatic glucose sensors. In photoelectrochemistry, Cu2O-CuO heterostructures of anodic copper oxides with highly-developed surface area are attractive for water splitting. All the above-mentioned aspects of anodic copper oxides derived catalysts with state-of-the-art background have been reviewed within this paper.

A high-performance pseudocapacitive electrode based on CuO–MnO2 composite in redox-mediated electrolyte

In the present work, a simple and cost-effective precipitation approach was carried out to fabricate CuO nano-needle, and its electrochemical performance was evaluated in a redox-mediated electrolyte (2 M KOH and 0.3 M K3Fe(CN)6). A high specific capacitance of 2519 F/g was recorded at a specific current of 8 A/g. However, the electrode suffered from poor rate capability as the specific capacitance was rapidly decreased to 100 and 1 F/g when the specific current was increased to 30 and 50 A/g, respectively. The CuO nanoparticles were further modified with MnO2 by a hydrothermal method, and the resulting CuO–MnO2 (CMO6) electrode delivered a high specific capacitance of 539 F/g even at very high specific current of 50 A/g. The as-synthesized electrode materials were structurally and morphologically characterized using X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The electrochemical performances of the CuO and MnO2–CuO composites have been examined in detail. Synopsis Modification of pristine CuO nano-needles with MnO2 nanosheets improved the electrochemical performance of the material. The composite was able to deliver a high specific capacitance of 539 F/g even at very high specific current of 50 A/g.

Binder-free CuO nanoneedle arrays based tube-type sensor for H2S gas sensing

CuO nanoneedle arrays were directly prepared on the commercial ceramic tubes by magnetron sputtering and subsequent wet chemical etching and annealing. This brand-new fabrication of the tube-type gas sensor retains the high specific surface area of nanoneedle and avoids using binders that are generally used for coating gas-sensitive materials on the surface of the ceramic tube. The as-fabricated binder-free CuO nanoneedle arrays sensor exhibits a decent response of 76.50 % to 10 ppm H2S at a low temperature of 150 °C. The response decreases to 20.27 % as the relative humidity increases from 40 % to 80 %. Moreover, the sensor shows good selectivity, reproducibility, and long-term stability to a low concentration of 10 ppm H2S. This superior sensing performance can be attributed to the abundant surface reactive adsorption sites provided by CuO nanoneedle arrays and the sensitization effect of p-p nano-homojunctions that arose from the interlaced CuO nanoneedles.

A novel “off-on” electrochemiluminescence sensor based on highly efficient resonance energy transfer in C-g-C3N4/CuO nanocomposite

A signal “off-on” electrochemiluminescence resonance energy transfer (ECL-RET) sensor based on carboxylated graphene-like carbon nitride (C-g-C3N4) as donor and CuO nanoneedles as acceptor has been constructed. The distance between donor and acceptor is a critical factor for ECL-RET sensors. Herein, we used a new method to make CuO nanoneedles grow in situ on C-g-C3N4 to form a nanocomposite, largely reducing the distance between donor and acceptor and greatly improving ECL-RET efficiency. In this system, because the CuO could be reduced by dopamine (DA), the ECL emission was significantly enhanced. Hence, a sensitive ECL sensor was successfully fabricated for quantitative detection of DA in dopamine hydrochloride injection and human serum sample. Further, the ECL-RET sensor exhibited a wide linear range from 10 nM to 1 mM, as well as a low detection limit of 8.2 nM. With its excellent stability and selectivity, the novel strategy will enable numerous applications in biological systems.

Ultrafast Growth of a Cu(OH)2–CuO Nanoneedle Array on Cu Foil for Methanol Oxidation Electrocatalysis

A swift potentiostatic anodization method for growing 5-7 µm tall nanoneedle array of Cu(OH)2-CuO on Cu foil within 100 s has been developed. This catalytic electrode when screened for methanol oxidation electrocatalysis in 1 M KOH with 0.5 M methanol, delivered a current density as high as 70 ± 10 mA cm-2 at 0.65 V vs. Hg/HgO which is superior to the performance of many related catalysts reported earlier. Observed activity enhancement is attributed to the formation of both Cu(OH)2-CuO nanoneedle array of high active surface area over the metallic Cu foil. In addition, Cu(OH)2-CuO/Cu electrode had also exhibited excellent stability upon prolonged potentiostatic electrocatalytic oxidation of methanol while retaining the charge transfer characteristics. Growth of such highly ordered assembly of Cu(OH)2-CuO nanoneedles has never been achieved before within a minute. When compared to its OER activity, the addition of 0.5 M methanol has lowered the overpotential at 10 mA cm-2 by 334 mV which is significant. This encourages the use of methanol as a sacrificial anolyte for energy-saving production of H2 from water electrolysis.

Fabrication and characterization of needle shaped CuO nanoparticles and their application as photocatalyst for degradation of organic pollutants

Fabrication of nanomaterials for deprivation of organic pollutants like dyes is important. In present research work spotlight is on preparation of copper oxide (CuO) nano needles and characterized by using various techniques such as ultraviolet (UV)–visible spectroscopy, X-ray diffraction (XRD) and Transmission electron microscopy (TEM). The photocatalytic efficiency of CuO nano needles has been examined on both kind of dyes such as cation dye (Victoria Blue) and anionic dye (Direct Red 81). CuO nano needles catalytic efficiency in degradation of dye was measured by examining the change in absorbance of dye under UV-spectrophotometer. The effects of functional parameters such as catalyst amount, pH and initial dye concentration were explored. CuO nano needles demonstrated brilliant degradation capacity in the existence of UV–visible radiations. Degradation processes follows pseudo-first order kinetics. The rate constant was fruitfully launched and reusability experiments were made to assure the steadiness of the used catalysts.

Orange Peel Derived C‐dots Decorated CuO Nanorods for the Selective Monitoring of Dopamine from Deboned Chicken

AbstractA novel electrode based on orange peel derived C‐dots decorated CuO nanorods (CR@C‐dot) modified lead pencil (LP) electrode has been fabricated for highly sensitive and selective monitoring of dopamine (DA). Prior to the functionalization with C‐dot, electrochemical efficacy of CR was evaluated and compared with CuO nano‐needles (CN) and nano‐spheres (CS). The morphology, surface area and composition of synthesized nanoparticles was confirmed through field emission scanning electron microscopy (FE‐SEM), N2‐adsorption‐desorption isotherm, X‐ray diffraction (XRD), Raman spectroscopy and X‐ray photoelectron spectroscopy (XPS). Our results indicated that CR has high electrocatalytic activity compared to CN and CS by expositing greater fraction of catalytic active sites, large surface area and short diffusion pathways. The electrochemical efficacy of CR is further enhanced by decorating with orange peel derived C‐dots, which surprisingly lead to the integrations of surface‐active sites with current collectors with minimum resistance by acting as an electron transport mediator and providing more surface defects. The developed CR@C‐dot sensor enables highly sensitive and selective recognition of DA detection (0.0007 μM), over good linear range (5–2250 μM) with rapid response time. the developed CR@C‐dot sensor was successfully used to monitor the DA from deboned chicken, thus suggesting reliability of the developed electrode.

Effect of the Cu foam pretreatment in the growth and inhibition of copper oxide nanoneedles obtained by thermal oxidation and their evaluation as photocathodes

Cu2O-CuO layers were prepared in situ on copper foam substrates by thermal oxidation at 400 °C in air using different pretreatments with acetone, HCl and NaOH. The effect of the pretreatment in the shape and physicochemical properties of the Cu2O-CuO layers, as well as in the growth or inhibition of the copper oxide nanostructures was studied, and a growth mechanism is proposed. It was found that the pretreatment modulates the nucleation and growth of the copper oxide nanostructures, being the process with NaOH the most suitable to promote the formation of well-defined nanoneedles, while in the case of the samples pretreated with acetone and HCl, copper oxide layers with irregular shape microstructures were obtained. The composition, structural, morphological and optical properties of the copper oxide structures were determined by X-ray diffraction, scanning electron microscopy, UV-vis diffuse reflectance and photoluminescence spectroscopy. The results showed that in all cases, the presence of both copper oxides, Cu2O and CuO was observed, with an optical band gap of 1.0 and 1.3 eV. The copper oxide structures exhibited photoluminescence emission centered at 551 nm, related to the recombination of the electron-hole pairs in the samples. The materials prepared with a NaOH pretreatment showed the lower emission and recombination rate.Moreover, the 3D Cu-Cu2O-CuO based materials were evaluated as photocathodes in a 0.5 M Na2SO4 solution and under Xe lamp illumination. The photoelectrode where 1D nanostructures were grown, exhibited the lower resistance to the charge transference in the Nyquist plots, the highest current density in the linear voltammetry and the highest photoresponse in the on-off light experiments. The improved electrical and physicochemical properties of the samples pretreated with NaOH was related to the particular 1D nanoneedle morphology, which promoted higher conductivity and photoresponse, lower resistance to the charge transference and lower recombination of free charge carriers, demonstrating the potential use of these electrodes for photoelectrochemical applications. Finally, this work proved that it is possible to grow well-defined and highly crystalline CuO nanoneedles on copper foam porous substrates through a simple, fast and clean method.

Development of biocompatible 1D CuO nanoneedles and their potential for sensitive, mass-based detection of anti-tuberculosis drugs

Unique physical and chemical properties make 1D nanomaterials very attractive and their window of applications is broadened by the addition of biocompatible materials. Similarly, the massive side effects associated with the frequent use of antibiotics make it crucial to analyze the quantity and detect even the subservient amounts of antibiotics in vivo following their administration to patients. The present study describes the one-pot solvothermal approach to produce 1D CuO nanoneedles. Microscopic investigations revealed the presence of nanoneedles of about 8–15 nm in size with negative surface charge (− 30.51 mV). These structures were explored for the targeted detection of the anti-tubercular agent rifampicin. This developed interface showed excellent sensitivity, with the limit of detection as low as 9.4 nM and the limit of quantification as 20 nM. This sensor exhibited good selectivity towards the structural analogs (rifabutene, rifapentine) of the analyte. This study represents the potential of 1D nanomaterial in biomedical applications such as the development of interfaces for online monitoring.

Growth of CuO nanoneedles on graphene quantum dots as peroxidase mimics for sensitive colorimetric detection of hydrogen peroxide and glucose

Graphene quantum dots-copper oxide nanocomposites (GQDs/CuO) are facilely fabricated by the growth of CuO nanoneedles on graphene quantum dots under mild conditions. The as-prepared GQDs/CuO nanocomposites could be used as an effective peroxidase mimics to catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2 to produce a blue-colored solution. Investigations on the mechanism indicate that the nature of peroxidase-like activity of GQDs/CuO nanocomposites originates from OH radical generation. The increase of absorbance at 652nm induced by the catalytic effect of GQDs/CuO nanocomposites offers accurate detection of H2O2 in the range of 0.5–10μM, along with a detection limit of 0.17μM. A colorimetric method for serum glucose detection is also proposed by combining the GQDs/CuO catalytic reaction and the enzymatic oxidation of glucose with glucose oxidase. This method is simple, sensitive and selective for glucose detection with a linear range from 2 to 100μM with a detection limit of 0.59μM.

Thermally oxidation synthesis of CuO nanoneedles on Cu foam and its enhanced lithium storage performance

In this work, CuO nanoneedles have been in situ grown on Cu foam through simple thermal oxidation in the air. The morphologies and microstructures of as-prepared sample were characterized by using X-ray diffraction, Raman spectrum, scanning electron microscopy, transmission electron microscopes. It was found that the one-dimensional CuO nanoneedles with single crystalline were uniform distributed upon the layer of Cu foam’s skeleton. Directly using the as-prepared sample as the anode material for lithium-ion battery, the electrochemical performances of CuO nanoneedles on Cu foam were investigated by galvanostatic discharge–charge tests, cyclic voltammetry, as well as impedance spectroscopy measurement. The in situ growth electrode without binder realized an initial capacity as high as 940 and 446 mAh g−1 still retained even after 100 cycles of charging and discharging. The superior lithium storage performance may be attributed to the unique hierarchical architectured of nanoneedles on skeleton of porous foam, which offers excellent electro-conductivity for the intimate contact between CuO active material and Cu foam current collector, and provides a large surface to volume ratio that favors lithium-storage. The results propose that the as-prepared CuO nanoneedles on Cu foam would be a potential anode material for lithium-ion battery applications.