CuO Nanoribbons Research Articles

Near 100% Conversion of Acetylene to High-purity Ethylene at Ampere-Level Current.

Direct production of high-purity ethylene from acetylene using renewable energy through electrocatalytic semi-hydrogenation presents a promising alternative to traditional thermocatalytic processes. However, the low conversion of acetylene results in a significant amount of acetylene impurities in the product, necessitating additional purification steps. Herein, a tandem electrocatalytic system that integrates acetylene electrolyzer and zinc-acetylene battery units for high-purity ethylene production is designed. The ultrathin CuO nanoribbons with enriched oxygen vacancies (CuO1-x NRs) as electrocatalysts achieve a remarkable 93.2% Faradaic efficiency of ethylene at an ampere-level current density of 1.0Acm-2 in an acetylene electrolyzer, and the power density reaches 3.8mWcm-2 in a zinc-acetylene battery under acetylene stream. Moreover, the tandem electrocatalysis system delivers a single-pass acetylene conversion of 99.998% and ethylene selectivity of 96.1% at a high current of 1.4A. Experimental data and calculations demonstrate that the presence of oxygen vacancies accelerates water dissociation to produce active hydrogen atoms while preventing the over-hydrogenation of ethylene. Furthermore, techno-economic analysis reveals that the tandem system can dramatically reduce the overall ethylene production cost compared to the conventional thermocatalytic processes. A novel strategy for complete acetylene-to-ethylene conversion under mild conditions, establishing a non-petroleum route for the production of ethylene is reported.

Sr2+-Doped CuO Nanoribbons with the Hydrophobic Surface Enabling CO2 Electroreduction to Ethane.

Electrochemical reduction of carbon dioxide to value-added multicarbon (C2+) products is a promising way to obtain renewable fuels of high energy densities and chemicals and close the carbon cycle. However, the difficulty of C-C coupling and complexity of the proton-coupled electron transfer process greatly hinder CO2 electroreduction into specific C2+ products with high selectivity. Here, we design an electrocatalyst of Sr-doped CuO nanoribbons with a hydrophobic surface for CO2 electroreduction to ethane with high selectivity. Sr doping enhances the chemical adsorption and activation of CO2 by inducing oxygen vacancies and increasing *CO coverage by stabilizing Cu2+ active sites, thus further boosting subsequent C-C coupling. The hydrophobic surface with dodecyl sulfate anions (DS-) adsorption increases the oxophilicity of the catalyst surface, enhancing the conversion of the *OCH2CH3 intermediate to ethane. As a result, the optimized Sr1.97%-CuO exhibits a Faradaic efficiency of 53.4% and a partial current density of 13.5 mA cm-2 for ethane under a potential of -0.8 V. This study provides a strategy to design a Cu-based catalyst by alkaline earth metal ions doping with the hydrophobic surface to engineer the evolution of the intermediates for a desired product during CO2RR.

Effect of PVP surfactant on the synthesis of CuO nanoribbons by the chemical reduction method

This work developed a simple and time-dependent method to synthesize CuO nanoribbons. For this, the concentration of the precursor salt (CuCl2), surfactant (PVP), and reaction times were varied, keeping constant the reducing agent (NaBH4). SEM, TEM, XRD, and EDS characterized CuO ribbon-like particles' morphology, chemical composition, and structure. SEM studies confirmed that CuO nanoribbons appear after three weeks of reaction aging by mixing CuCl2 (17 mM), NaBH4 (26 mM), and PVP (1.6 mM). The nanoribbons have a relatively low aspect ratio of 2 to 3 µm long and around 60 nm wide. XRD and TEM confirmed the monoclinic structure of the CuO nanoribbons. SEM micrographs also indicated that as the salt concentration decreases to 10 mM, the size of the products decreases, and nanosheet-like nanostructures with lengths less than 1 μm and thicknesses of 100 nm are formed. PVP was found to have a great influence on the morphology of the nanostructures. For example, low amounts of PVP increase particle oxidation, easily driving the formation of CuO nanoribbons. At the same time, larger amounts stabilize the formation of Cu2O octahedral particles.

Magnetism in Zigzag and Armchair CuO Nanoribbons: Ab Initio Analysis

The present work reports the magnetism analysis of zigzag and armchair forms of CuO nanoribbons by using density functional theory (DFT)-based ab initio approach. The structural stability has been confirmed through the binding energy calculation. The electronic and magnetic properties have been analyzed as a function of varied width of CuO nanoribbons, interesting information for variety of applications. The metallic and ferromagnetic behaviors of CuO nanoribbons are observed, whereas its bulk counterpart shows a p-type semiconducting and antiferromagnetic nature. The computed magnetic moments for the zigzag and armchair forms of CuO nanoribbon are in the ranges of 0.19–0.61 μB and 0.24–0.97 μB, respectively. The computed spin polarizations confirms the half or full metallic ferromagnetic nature of these nanoribbons.

An enhanced ultra-fast responding ethanol gas sensor based on Ag functionalized CuO nanoribbons at room-temperature

An ultra-fast responding ethanol gas sensor based on the Ag-functionalized CuO nanoribbons was fabricated by a wet chemical method. Results indicated that Ag nanoparticles were on the surface of the CuO nanoribbons in the form of metallic Ag. The gas sensor performance based on CuO nanoribbons was remarkably enhanced by decorating with Ag nanoparticles. All results reveal that the Ag–CuO nanoribbons exhibit higher response and ultra-fast response time characteristic than CuO nanoribbons at room temperature. Particularly, the response time of the gas sensor based on Ag–CuO nanoribbons was about 2 s, which was five times shorter than that of the bare CuO nanoribbons.

Enhanced field emission properties of CuO nanoribbons decorated with Ag nanoparticles

The structural and field emission properties of CuO nanoribbons decorated with Ag nanoparticles by a wet chemical method were investigated. The results demonstrated a remarkable enhancement of field emission performance of CuO nanoribbons decorated with Ag nanoparticles. The effect of Ag amount on the field emission performance was studied in detail, and excellent field emission properties such as a low turn-on electric field of 2.1V/μm and a high field enhancement factor of 2528 were obtained.

Novel synthesis process for solar-light-active porous carbon-doped CuO nanoribbon and its photocatalytic application for the degradation of an organic dye

A simple, one-step novel solution process was developed for the synthesis of carbon-doped CuO (C-CuO) nanoribbons without the use of a catalyst, template, substrate, or costly instrumentation at room temperature.

Room temperature light-induced recrystallization of Cu2O cubes to CuO nanostructures in water

Visible light irradiation induces recrystallization of Cu2O cubes to [010] growth-directed CuO nanoribbons in water due to the creation of active ˙OH and ˙O2− species and outward Cu diffusion along unstable {010} facets.

Rapid synthesis of CuO nanoribbons and nanoflowers from the same reaction system, and a comparison of their supercapacitor performance

One-dimensional CuO nanoribbons and three-dimensional CuO nanoflowers were synthesized via a facile, rapid, low-temperature, one-pot water bath method, in which the synthesis was performed in Cu(CH3COO)2/NaOH and aqueous/ethanol systems at 70 °C for 15 min. Control over the shape and dimensionality of the well-defined CuO single crystals was achieved simply by varying the order of addition of the reactive materials. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and selected area electron diffraction were used to characterize the products. The formation mechanism in the in situ, rapid reaction was investigated. In Brunauer-Emmett-Teller and thermogravimetry measurements, the nanoribbons exhibited a higher specific surface area and higher adsorption capabilities than the nanoflowers. Using cyclic voltammetry, chronopotentiometry and EIS measurement for supercapacitance, it was shown that the nanoflower electrodes had better performance than the nanoribbon electrodes, however, the nanoribbon/C electrodes had better performance than the nanoflower/C electrodes at lower current density, but were worse at higher current density.

A chemical reaction controlled mechanochemical route to construction of CuO nanoribbons for high performance lithium-ion batteries

We reported a chemical reaction controlled mechanochemical route to synthesize mass CuO nanosheets by manual grinding in a mortar and pestle, which does not require any solvent, complex apparatus and techniques. The activation of chemical reactions by milling reactants was thus proved, and the energy from mechanical grinding promotes the fast formation of CuO nanoribbons. The resultant materials have preferential nanoscale ribbon-like morphology that can show large capacity and high cycle performance as lithium-ion battery anodes. After 50 cycles, the discharge capacity of CuO nanoribbon electrodes is 614.0 mA h g(-1), with 93% retention of the reversible capacity. The thermodynamic reactions of the CuO battery showed size-dependent characterization. The microstructures of CuO nanosheets and reaction routes can be controlled by the ratio of NaOH/CuAc2 according to the chemical reactions involved. The intact nanoribbon structure, thin-layer, and hierarchical structures endow present CuO materials with high reversible capacity and excellent cycling performances. The simple, economical, and environmentally friendly mechanochemical route is of great interest in modern synthetic chemistry.

Facile Synthesis of Mesoporous CuO Nanoribbons for Electrochemical Capacitors Applications

Facile Synthesis of Mesoporous CuO Nanoribbons for Electrochemical Capacitors Applications

Tailoring CuO nanostructures for enhanced photocatalytic property

We report on one-pot synthesis of various morphologies of CuO nanostructures. PEG200 as a structure directing reagent under the synergism of alkalinity by hydrothermal method has been employed to tailor the morphology of CuO nanostructures. The CuO products have been characterized by XRD, SEM, and TEM. The morphologies of the CuO nanostructures can be tuned from 1D (nanoseeds, nanoribbons) to 2D (nanoleaves) and to 3D (shuttle-like, shrimp-like, and nanoflowers) by changing the volume of PEG200 and the alkalinity in the reaction system. At neutral and relatively low alkalinity (OH−/Cu2+≤3), the addition of PEG200 can strongly influence the morphologies of the CuO nanostructures. At high alkalinity (OH−/Cu2+≥4), PEG200 has no influence on the morphology of the CuO nanostructure. The different morphologies of the CuO nanostructures have been used for the photodecomposition of the pollutant rhodamine B (RhB) in water. The photocatalytic activity has been correlated with the different nanostructures of CuO. The 1D CuO nanoribbons exhibit the best performance on the RhB photodecomposition because of the exposed high surface energy {−121} crystal plane. The photocatalytic results show that the high energy surface planes of the CuO nanostructures mostly affect the photocatalytic activity rather than the morphology of the CuO nanostructures. Our synthesis method also shows it is possible to control the morphologies of nanostructures in a simple way.

Preparation of hierarchical dandelion-like CuO microspheres with enhanced catalytic performance for dimethyldichlorosilane synthesis

Hierarchical dandelion-like CuO (HD–CuO) microspheres composed of nanoribbons were prepared via a facile hydrothermal method. The samples were characterized by nitrogen adsorption, X-ray diffraction, temperature-programmed reduction, thermogravimetric analysis, transmission electron microscopy and scanning electron microscopy. It was found that the reaction temperature, reaction time and reagent amounts had a significant effect on the morphology and structure of HD–CuO. The obtained HD–CuO microspheres possessed a surface area of 10.6–57.5 m2 g−1 and a diameter of 3–6 μm. In the formation process, ethylene glycol was adsorbed on the surface of the CuO nanoribbons and it acted as the structure-directing agent and thereafter the CuO nanoribbons were self-assembled into HD–CuO. The investigation of the Rochow reaction showed that the HD–CuO catalyst had a better catalytic performance in dimethyldichlorosilane synthesis than the commercial CuO microparticles and commercial CuO–Cu2O–Cu catalyst, owing to its well-developed hierarchically porous structure and higher specific surface area, leading to the increased contact interface among reaction gas, solid catalyst and solid silicon, together with enhanced mass transportation.

Synthesis of CuO nanowalnuts and nanoribbons from aqueous solution and their catalytic and electrochemical properties

One dimensional copper hydroxide nanostrands, two dimensional Cu(2)(OH)(3)NO(3) nanoribbons and three dimensional CuO nanowalnuts were synthesized from the same diluted copper nitrate solution with ethanolamine at room temperature and 10 °C, respectively. The Cu(2)(OH)(3)NO(3) nanoribbons were formed by slowly hydrolyzing ethanolamine at low temperature. The CuO nanowalnuts were formed through dehydration of copper hydroxide nanostrands in aqueous solution at room temperature. Although their average size is about 500 nm, the specific surface area of the CuO nanowalnuts can be as large as 61.24 m(2) g(-1), due to their particular morphology with assembling of 8 nm grains. The Cu(2)(OH)(3)NO(3) nanoribbons were converted to CuO porous nanoribbons, keeping the shape. The catalytic performance of the CuO nanowalnuts for CO oxidation is 160 mL h(-1) g(cat)(-1) which is 23 times higher than those of the CuO porous nanoribbons and 40 nm commercial CuO nanoparticles, respectively. The electrochemical properties of the CuO nanowalnuts were also examined in a lithium-ion battery. After 30 cycles, the capacity of the as-prepared CuO nanowalnuts could sustain 67.1% (407 mA h g(-1)) of the second cycle (607 mA h g(-1)) at a rate of 0.1 C.

Cu(OH) 2 and CuO nanotube networks from hexaoxacyclooctadecane-like posnjakite microplates: Synthesis and electrochemical hydrogen storage

Our recent progress shows that Cu(OH) 2 and CuO nanoribbon arrays exhibit notable electrochemical hydrogen storage capacities of 180 and 160 mAh/g, respectively, which also suggests that porous or tubular nanostructures can have a higher ability of hydrogen uptake. Two dimensional (2D) networks consisting of crossed Cu(OH) 2 nanotubes were prepared by a simple topotactic transformation process, including the fabrication of hexaoxacyclooctadecane-like intermediate posnjakite microplates and their subsequent chemical transformation into Cu(OH) 2 nanotube networks, which further dehydrated to produce CuO nanotube networks with partial morphological preservation. The formation of half-tube and half-ribbon structures, nanoribbons, and nanotubes during the transformation processes revealed that the deformations of corrugated posnjakite sheets to give lamellar Cu(OH) 2 with rolling into tubular structures could be responsible for the growth of Cu(OH) 2 nanotube networks from posnjakite microplates. The Cu(OH) 2 and CuO nanotube networks could electrochemically charge and discharge with higher hydrogen storage capacities of 220 and 188 mAh/g than the Cu(OH) 2 and CuO nanoribbon arrays at room temperature, respectively, which made them promising candidates for hydrogen storage, high-energy batteries and catalytic fields. Based on the rolling mechanism of layered structural materials, this simple topotactic transformation route might be extendable to the preparation of novel nanotube networks with higher capacities of hydrogen storage if appropriate precursors of numerous materials with layered structures were treated in solution.

One-pot sonochemical fabrication of hierarchical hollow CuO submicrospheres

Hierarchical hollow CuO submicrospheres have been fabricated on a large scale by a facile one-pot sonochemical process in the absence of surfactants and additives. The as-prepared products were investigated by XRD, FESEM, EDX, TEM, SAED, HRTEM and BET nitrogen adsorption–desorption isotherms. The results reveal that hollow pumpkin-shaped structures possess a monoclinic phase CuO with the diameters ranging from 400 to 500 nm, and their walls with around 45 nm in thickness are composed of numerous single crystalline CuO nanoribbons with a width of about 8 nm. The BET specific surface area of the as-synthesized CuO hollow structures was measured to be 59.60 m 2/g, and the single point adsorption total pore volume was measured to be 0.1036 cm 3/g. A possible growth mechanism for the formation of hierarchical hollow CuO structures was proposed, which is considered to be a sonohydrolysis – oriented aggregation – Ostwald ripening process. The novel hollow CuO spherical structures may utilize applications in biosensors, photonics, electronics, and catalysts.

One-step fabrication of CuO nanoribbons array electrode and its excellent lithium storage performance

CuO nanoribbons array (NRA) electrode was fabricated by developing a one-step synthesis route, which consists of advantages of large-scale, fast, and without using any surfactant or template. The structure and electrochemical properties of the CuO NRA electrode were examined by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV) and galvanostatic cycling. The results demonstrated that the CuO NRA electrode can deliver a reversible capacity as high as 608 mAh g −1 up to 275th cycle. The excellent cycleability, the high capacity retention and the high rate-capability of the CuO NRA electrode is attributed to its peculiar nanostructure with large surface area, numerous interspaces of the CuO nanoribbons, and the solid adhesion of the active material to Cu current collector.

Synthesis of CuO nanoribbon arrays with noticeable electrochemical hydrogen storage ability by a simple precursor dehydration route at lower temperature

CuO nanoribbon arrays were synthesized by a simple dehydration reaction for the first time. The products exhibit excellent hydrogen storage capacity and big BET surface area. The present work shows that the nanostructures of products are important to their electrochemical hydrogen storage performances. Further research will be performed on more novel cupreous 1D nanoarrays exhibiting different electrochemical hydrogen storage performances, in which more excellent hydrogen storage materials might be found. On the other hand, the low cost, convenient process, good reproducibility, high yield, and clean reactions of the present synthetic method make it possible to scale it up to industrial production.

Facile fabrication of Cu(OH)2 and CuO nanoribbon arrays by silver-mediated oxidation

Cu(OH)2 and CuO nanoribbon arrays have been facilely fabricated on copper foil by silver-mediated oxidation in the mixed aqueous solution of Na2O2 and AgNO3 at room temperature.

Chemical synthesis, characterisation and gas sensing performance of copper oxide nanoribbons

Single crystalline copper oxide nanoribbons were synthesized via a surfactant-assisted hydrothermal route. The resulting CuO nanoribbons contain substantial amounts of nanorings and nanoloops. High resolution TEM analysis identified CuO nanoribbons growing along the [010] direction. CuO nanoribbons exhibited excellent sensing performance towards formaldehyde and ethanol vapours with rapid response and high sensitivity at low operating temperatures. We found that the loading of a small amount of Au or Pt nanoparticles on the surface of CuO nanoribbons can effectively enhance and functionalize the gas sensing performance of CuO nanoribbons.