Copper Cobalt Research Articles

Facile Electrochemical Synthesis of Highly Efficient Copper–Cobalt Oxide Nanostructures for Oxygen Evolution Reactions

Nanostructured copper–cobalt oxide (CuxCo3−xO4, CCO) electrodes are grown directly on conducting substrates via electrochemical deposition; then, various factors (e.g., oxygen vacancies, electrochemically active surface area, and electrical conductivity) affecting their electrocatalytic activity for oxygen evolution reactions (OERs) are studied. The observed OER performance decreases when increasing the annealing temperature due to the nanostructure deformation and agglomeration and the decreased number of oxygen vacancies, electrochemically active surface area, and electrical conductivity. An optimized nanopetal structure of CuxCo3−xO4 (x = 0.95, annealed at 200 °C) shows a considerably high Faradaic efficiency (∼93%) with a remarkably low overpotential (∼230 mV) at a benchmark current density (J) of 10 mA cm−2; at the same J in an alkaline solution (1 M KOH) for OER, it also exhibits high durability (up to 100 h). This study provides a complete guide for designing efficient and robust spinel-type CCO electrocatalysts through a facile electrochemical route.

Studies on continuous selective hydrogenolysis of glycerol over supported Cu–Co bimetallic catalysts

Alumina supported copper–cobalt catalysts were made and screened for continuous hydrogenolysis of glycerol to 1,2-propanediol at atmospheric pressure.

Superior performance and stability of anion exchange membrane water electrolysis: pH-controlled copper cobalt oxide nanoparticles for the oxygen evolution reaction

Cu0.5Co2.5O4 nanoparticles are obtained by changes in the pH and applied as the anode in anion exchange membrane water electrolysis.

Space-Confined Synthesis of Lasagna-like N-Doped Graphene-Wrapped Copper–Cobalt Sulfides as Efficient and Durable Electrocatalysts for Oxygen Reduction and Oxygen Evolution Reactions

Searching for efficient and economical bifunctional oxygen electrocatalysts is urgent for exploring sustainable energy technologies. Herein, the unique lasagna-like structured copper–cobalt sulfide...

Structural, morphological and magnetic properties of Mn2+ ions substituted nanosized nickel–copper–cobalt ferrites through sol–gel auto-combustion method

Manganese substituted nickel–copper–cobalt ferrite nanoparticles having the basic composition [Formula: see text] (x = 0.0, 0.1, 0.2, 0.3 and 0.4) were synthesized by sol–gel auto-combustion method. X-ray diffraction (XRD) was used to estimate phase purity and lattice symmetry. All the prepared samples show the single-phase cubic spinel structure. Fourier transform infrared (FTIR) measurements also confirm the cubic spinel structure of the ferrite that is formed. The preparation of samples show these nearly spherical particles by Transmission electron microscopy (TEM). The magnetic properties of Mn[Formula: see text] ion substituted in nickel–copper–cobalt ferrite were studied by Vibrating sample magnetometer (VSM). The saturation magnetization ([Formula: see text]), remanent magnetization [Formula: see text], coercivity [Formula: see text], magnetic moment [Formula: see text] and anisotropy constant [Formula: see text] first increase and then decrease with the increase of [Formula: see text] ions content. They had better magnetism than pure sample and other substituted samples when the substitution amount of [Formula: see text] ions was [Formula: see text]. At [Formula: see text], the maximum values of remanent magnetization [Formula: see text], saturation magnetization [Formula: see text] and coercivity [Formula: see text] are 25.58 emu/g, 61.95 emu/g and 689.76 Oe, respectively. This indicates that the magnetism of ferrite can improve by substituting with the appropriate amount of manganese. However, due to the excess [Formula: see text] ions instead, ferrite magnetism is weakened. This means that these materials can be used in magnetic data storage and recording media.

Ternary CuCo2S4 Thiospinel Nanocrystal-Coated Photodiode with Improved Photoresponsivity and Acceptance Angles for Optoelectronic Applications

Ternary-structured thiospinels have attracted great attention in recent years for energy applications due to their attractive characteristics such as simple production, earth-abundant components and non-toxic nature. In this work, copper cobalt sulfide (CuCo2S4 or carrollite) thiospinel nanocrystals were synthesized by a hot-injection method, and detailed electrical and optoelectronic characterizations were performed in a Schottky device. The synthesized nanocrystals were used as an interfacial layer between the Au metal and p-Si semiconductor to obtain an Au/CuCo2S4/p-Si device. The structural and morphological characterizations confirmed the crystallinity, nanostructure and composition of the CuCo2S4 nanocrystals. The I–V and C–V measurements were employed to characterize the Au/CuCo2S4/p-Si device for various illumination intensities. The obtained device exhibited good rectifying and photodiode properties as well as good photocapacitance. The Au/CuCo2S4/p-Si device can be used and improved for optoelectronic applications.

Advanced Cu0.5Co0.5Se2 nanosheets and MXene electrodes for high-performance asymmetric supercapacitors

Transition-metal chalcogenides (TMCs) have attracted numerous interests in the field of energy storage owing to their exceptional electrical conductivity, ultrahigh specific capacity, etc. Herein, with inspiration from the attractive nanostructures of hierarchical frameworks with interconnected networks, we endeavored to design ternary copper cobalt selenide (CuxCo1–xSe2) nanostructures through a facile and cost-effective hydrothermal and followed by selenization process. The effects of Cu2+ is investigated and shows significant enhancement in the electrochemical performances. The optimal Cu0.5Co0.5Se2 nanosheets (NSs) possess hierarchical architectures, large specific surface area, unique porous networks, and excellent intrinsic conductivity that result in superior electrochemical properties by their excellent synergistic effects. Taking advantage of the merits of the rational nanostructures, the Cu0.5Co0.5Se2 NSs significantly boost the capacitive performances as ultrahigh specific capacitance of ~1695 F g−1 at a current density of 1 A g−1, and long-term cycling stability (~94.9%). An asymmetric supercapacitor (ASC) device is fabricated using the Cu0.5Co0.5Se2 NSs as a positive electrode, and multilayered MXene (Ti3C2) as a negative electrode. Remarkably, the ASC operates at a working potential of 1.6 V and delivers a high energy density (~84.17 Wh kg−1 at 0.604 kW kg−1), high power density (~14.95 kW kg−1 at 57.73 Wh kg−1), and exceptional cycling stability (~91.1% after 10,000 charge–discharge cycles). The energy-storage properties are superior to recently reported TMCs-based ASC, proposing that the Cu0.5Co0.5Se2//MXene ASC has massive potential for next-generation energy-storage systems.

Sustainable Hydrogen Generation by Catalytic Hydrolysis of NaBH4 Using Tailored Nanostructured Urchin-like CuCo2O4 Spinel Catalyst

The present study describes the hydrogen production as a future energy source via hydrolysis of NaBH4 catalyzed by urchin-like CuCo2O4 spinel catalyst prepared by urea-assisted hydrothermal synthesis method. The as-synthesized copper–cobalt double hydroxide precursor and the resultant CuCo2O4 spinel were characterized by using various analytical, spectroscopic and microscopic techniques in order to understand their physiochemical and morphological aspects. The detail characterization results confirmed the successful formation of CuCo2O4 spinel phase with urchin-like morphology. The CuCo2O4 spinel catalyst was then tested for its application in hydrogen generation from NaBH4 hydrolysis by performing the reaction using 10 wt% of CuCo2O4 spinel catalyst and 0.5 g NaBH4 at room temperature. The CuCo2O4 spinel catalyst with tailored architecture displayed high catalytic activity with H2 generation rate of 1370 mL min−1 g−1 (1438 mL in 21 min). Major factors affecting the hydrolysis of NaBH4 reaction such as catalyst loading, NaOH concentration and temperature variation was also studied and discussed in detail. Correspondingly, the low activation energy of 22 kJ mol−1 was obtained from the Arrhenius plot and kinetic studies revealed that the hydrolysis of NaBH4 followed first order kinetics. Further, recyclability study of CuCo2O4 spinel catalyst was also performed which displayed good catalytic activity and stability even after five successive recycles. Characterization data of reused catalyst revealed that physiochemical properties of fresh CuCo2O4 spinel catalyst were well-preserved in the reused catalyst as well. Therefore, nanostructured CuCo2O4 spinel can be demonstrated as one of the most efficient, cost effective bimetallic spinel catalyst so far for application in the hydrogen generation.

Development of Copper Cobalt Sulfide with Cu : Co Ratio Variation on Carbon Cloth as an Efficient Electrode Material for the Oxygen Evolution Reaction

AbstractWhen designing a device for energy conversion, development of a highly active catalyst for OER (oxygen evolution reaction) reaction in alkaline medium is of utmost importance. For energy conversion, herein, we developed copper cobalt sulfide on carbon cloth (CC) using a simple and facile hydrothermal method. A vertically grown 2D sheet‐like structure of copper‐cobalt sulfide is observed using L‐cysteine as a sulfur source. An optimized ratio of copper(II) and cobalt(III) and the best sulfur source are found to boost the electrocatalytic activity of mixed metal thiospinel for OER. Several characterization techniques (XRD, Raman, FESEM, TEM, XPS, and ICP‐AES) were used to confirm phase purity, morphology, and composition of copper cobalt sulfides. We have established that 2D nanosheets of CuCo3Sz/CC exhibited superior electrocatalytic performance over bare RuO2 in 1.0 M KOH solution. It is observed that CuCo3Sz/CC need only 105 mV overpotential to generate 5 mA/cm2 current density. CuCo3Sz/CC is very stable and able to produce unaltered current density under an applied potential of 1.615 V vs. RHE for 48 h. Electrochemically active surface area calculation is performed for all catalysts to confirm higher electrocatalytic activity. The catalyst, CuCo3Sz/CC is used in a broad pH region using 0.5 M KOH, saline water, and 0.5 M Na2SO4 electrolyte solution to widen the applicability of water splitting. This work shows an avenue to develop active and durable electrocatalyst for OER without using any noble metal electrocatalyst.

Hydrogen bubble template fabricated nano-architecture quaternary dendritic sulfide as cathode and electro-etched carbon fiber paper as anode electrode for total novel binder-free asymmetric supercapacitors

A novel electrode consisting of 3D porous nickel‒cobalt‒copper sulfide dendritic structures is synthesized, in which, for the first time ternary Ni–Co–Cu foam is constructed through hydrogen bubble template and followed by sulfidization via a hydrothermal reaction in thiourea. The 3D, porous Ni–Co–Cu dendritic sulfide electrode exhibits a high specific capacitance of 1203.75 F g−1 (0.963 F cm−2) at current of 1.0 mA and excellent cycling stability, excellent ratability along with high cycle stability. An asymmetric supercapacitor (ASC) using dendritic sulfide structures and reduced electro-etched carbon fiber paper (RECF) as the positive and negative electrodes, respectively is developed. RECF is prepared through electrochemical oxidation process in acidic solution followed by electrochemical reduction, which exhibits a high areal capacitance of 695 mF cm−2 at current of 1.0 mA. The assembled device can be operating reversibly between 0 and 1.6 V and provides high specific capacitance of 178.5 mF cm−2 and an excellent cycling stability of 97.3% after 1000 cycles. This work exploits a pathway to construction of dendritic sulfides of quaternary metal foams that could be used for any flat metal substrate and open a new doorway to quaternary transition metal sulfides electrode materials in energy storage and conversion devices.

Copper–Cobalt Thermoelectric Generators: Power Improvement Through Optimized Thickness and Sandwiched Planar Structure

In this paper, metallic thermoelectric generators were studied and fabricated using copper (Cu) and cobalt (Co) as their respective positive and negative thermoelements. Thus, the chosen Cu-clad polyimide substrate alleviated the deposition of Cu and eased the microfabrication. A lateral device structure might assist in generating larger output power through its longer thermoleg length. Hence, the fabricated thick-film devices had planar and lateral structures with lateral heat flow and lateral thermopile layout. The strong correlations of electrical and thermal conductivities in metal thermoelements have resulted in lower Seebeck coefficient along with reduced thermoelectric power-generating performances. Alternatively, a thermoleg cross-sectional area ( ${A}$ ) optimization approach may optimize these disrupting correlations and improve their power-generating effectiveness, whereas a sandwiched planar structure can allow more thermopiles to be integrated without influencing the generator’s size. Both A optimization and sandwiched planar structure have rarely been applied and studied in the past works and have never been implemented using metal thermoelements. Hereafter, a Cu–Co device was enhanced through ${A}$ optimization by increasing the thickness of Co over 3.86 times the Cu thickness, and the implementations of a sandwiched planar structure. Herein, a flexible sandwiched planar thermoelectric generator was fabricated for the first time, using simpler microfabrication. This enhanced Cu–Co generator achieved a thermoelectric efficiency factor of ${6.6} \times {10}^{-{3}}\,\,\mu $ Wcm−2K−2( $12.89~\mu $ Wcm−2) at a temperature difference of 44.2 K. It remarked 3.1 times of improvement (by stacking three sets of thermopile) than its similar single Cu–Co thermopile of ten thermocouples.

Fabrication of N-doped carbon coated spinel copper cobalt sulfide hollow spheres to realize the improvement of electrochemical performance for supercapacitors

Metal sulfides with spinel structures have been considered as promising materials for supercapacitors and attracted increasing attentions of researchers over the past few years. However, inherent defects of metal sulfides such as poor electric conductivity and cyclic stability limit the practical application. Herein, we present a facile strategy to fabricate N-doped carbon coated spinel copper cobalt sulfide hollow spheres with remarkable electrochemical performance. A kind of Cu–Co coordination polymer spheres was utilized as template and metal precursor, polydopamine modified on the surface of the spheres was the source of N-doped carbon. The optimized hybrid materials exhibit high specific capacitance (1228 F g−1 at 1 A g−1) and outstanding cyclic stability (retaining 81.5% of the initial capacitance after 10000 cycles at 20 A g−1). The result demonstrates that this hybrid material is a promising electrode material to realize high performance supercapacitors.

Cu–Co‐codoped titanate/TiO2nanocomposite thin films for enhanced visible light absorption

Titanate nanotube thin (TNT) films were synthesised by alkaline hydrothermal method using titanium (Ti) plates as precursors. Copper–cobalt (Cu–Co)-codoped titanate/Ti dioxide (TiO2) nanocomposite thin films were prepared by doping Cu and Co to TNT films through ion exchange method and annealed at 500°C for 120 min. The as-prepared nanocomposite films were characterised by scanning electron microscopy, transmission electron microscopy, X-ray diffractometer, and ultraviolet–visible absorption spectra. The results show that anatase TiO2 particles were grown on the surface of titanate nanomaterial films. The composite materials mainly consisted of anatase TiO2 particles and titanate nanotubes/nanosheets. Cu–Co-codoped titanate/TiO2 nanocomposite thin films exhibited superior visible height adsorption property due to the reduced energy bandgap of composites introduced by additional Cu and Co 3d orbitals.

Effect Cr3+ Ion Substitution on the Structural, Magnetic, and Dielectric Behavior of Co–Cu Ferrite

Cr3+ substituted cobalt–copper ferrites with chemical composition Co0.9Cu0.1Fe2−xCrxO4 (where x = 0.00, 0.03, 0.06, 0.09, 0.12, and 0.15) were prepared by sol–gel mediated auto combustion route utilizing malic acid as a complexing agent. The effect of incorporation of Cr3+ ions in low concentration on the structural, magnetic, dielectric, and electrical features of the Co–Cu ferrite compounds was investigated. The crystalline nature and variation in crystallite size with substituent content were identified from X-ray diffraction. Cr3+ substitution for Fe in the Co–Cu ferrite leads to a monotonic decrease in the saturation magnetization at 300 K as well as at 50 K, which could be credited to the decrease in strength of superexchange interaction on the substitution of Fe3+ ions by weakly magnetic Cr3+ ions in the octahedral site. Substitution of small fractions Cr3+ ions for some of the Fe in cobalt–copper ferrites decreased the Curie temperature. A decreasing pattern in DC resistivity with an increase in temperature was observed ensuring the semiconducting character of the ferrites under test. Dielectric properties such as dielectric constant (e′) and dielectric loss (tan δ) of prepared materials were investigated.

Persulfate enhanced pollutants oxidation efficiency and power generation in photocatalytic fuel cell with anodic BiOCl/BiOI and cathodic copper cobalt oxide

Abstract In this paper, a photocatalytic fuel cell (PFC) system consisting of an anode with BiOI/BiOCl and a cathode with copper cobalt oxide, was investigated in to treating tetracycline and coking wastewater. Treating tetracycline (initial 100 mg/L), adding 20 mM persulfate (PS) in this PFC increased the pollutants degradation (from 74% in 1 h to 95% in 10 min, the kinetic constant from 0.021 min−1 and 0.296 min−1) and current density generation (from 1.7 × 10−3 mA/cm2 to 1.4 × 10−2 mA/cm2) and the open circuit voltage from 0.15 V to 0.38 V. Treating coking wastewater, the PFC/PS removed 90% TOC (initial 162 mg / L, pH 5) in 1 h, generating a current density of 1.2 × 10−2 mA/cm2 and open circuit voltage 0.42 V. The synergistic performance of PFC/PS is stable. The effects of persulfate concentration, initial pH and pollutant concentration on the kinetics and PFC performance were investigated and the synergy mechanism in PFC/PS was discussed.

Hierarchical copper cobalt sulfides nanowire arrays for high-performance asymmetric supercapacitors

Binary transition metal sulfides are considered to be promising electrode materials for high-performance supercapacitors because of their ultrahigh electron conductivity and superior electrochemical activity compared to the unitary transition metal sulfides. In this work, copper cobalt sulfides nanowire arrays on nickel foam with different element ratios and porosities are prepared by using a two-step hydrothermal method, and their electrochemical performance is explored. Benefited from the high electrical conductivity, rich active sites and optimized microstructure, the optimized copper cobalt sulfides (CuCo2S4) electrode can achieve a ultrahigh specific capacitance of 2446.6 F·g−1 at 1 A·g−1 and favorable rate performance. The asymmetric supercapacitor assembled with the CuCo2S4 nanowire array and activated carbon (AC) electrodes displays a high energy density of 33.4 Wh·kg−1 at a power density of 751.5 W·kg−1 can be obtained. Additionally, the assembled asymmetric cell shows a favorable capacitance retention of 78% after charging and discharging for 10,000 cycles at a high current density of 4 A·g−1.

Copper-Doped Cobalt Spinel Electrocatalysts Supported on Activated Carbon for Hydrogen Evolution Reaction.

The development of electrocatalysts based on the doping of copper over cobalt spinel supported on a microporous activated carbon has been studied. Both copper–cobalt and cobalt spinel nanoparticles were synthesized using a silica-template method. Hybrid materials consisting of an activated carbon (AC), cobalt oxide (Co3O4), and copper-doped cobalt oxide (CuCo2O4) nanoparticles, were obtained by dry mixing technique and evaluated as electrocatalysts in alkaline media for hydrogen evolution reaction. Physical mixtures containing 5, 10, and 20 wt.% of Co3O4 or CuCo2O4 with a highly microporous activated carbon were prepared and characterized by XRD, TEM, XPS, physical adsorption of gases, and electrochemical techniques. The electrochemical tests revealed that the electrodes containing copper as the dopant cation result in a lower overpotential and higher current density for the hydrogen evolution reaction.

Multicomponent Hierarchical Cu‐Doped NiCo‐LDH/CuO Double Arrays for Ultralong‐Life Hybrid Fiber Supercapacitor

AbstractFiber supercapacitors have aroused great interest in the field of portable and wearable electronic devices. However, the restrained surface area of fibers and limited reaction kinetics of active materials are unfavorable for performance enhancement. Herein, an efficient multicomponent hierarchical structure is constructed by integrating the Cu‐doped cobalt copper carbonate hydroxide@nickel cobalt layered double hydroxide (CCCH@NiCo‐LDH) core–shell nanowire arrays (NWAs) on Cu fibers with highly conductive Au‐modified CuO nanosheets (CCCH@NiCo‐LDH NWAs@Au–CuO/Cu) via a novel in situ corrosion growth method. This multicomponent hierarchical structure contributes to a large accessible surface area, which results in sufficient permeation of the electrolyte. The Cu dopant could reduce the work function and facilitate fast charge transfer kinetics. Therefore, the effective ion diffusion and electron conduction will facilitate the electrochemical reaction kinetics of the electrode. Benefiting from this unique structure, the electrode delivers a high specific capacitance (1.97 F cm−2/1237 F g−1/193.3 mAh g−1) and cycling stability (90.8% after 30 000 cycles), exhibiting superb performance compared with most oxide‐based fiber electrodes. Furthermore, the hybrid fiber supercapacitor of CCCH@NiCo‐LDH NWAs@Au–CuO/Cu//VN/carbon fibers is fabricated, providing a remarkable maximal energy density of 34.97 Wh kg−1 and a power density of 13.86 kW kg−1, exhibiting a great potential in high‐performance fiber‐shape energy‐related systems.

Synthesizing Ni-based ternary metal compounds for battery-supercapacitor hybrid devices with and without using nickel precursors

Hydrothermal method is widely used for synthesizing Ni-based metal oxides on Ni foam as the battery-type materials. The Ni ions for synthesizing Ni-based metal oxides can be obtained from the Ni precursor and the Ni foam, but the effect for the Ni ion source on the physical and electrochemical properties of the Ni-based metal oxides are still not clear. This work investigates the effects of the Ni precursor in the hydrothermal solution for synthesizing Ni-based metal oxides on morphology of metal oxides and electrocapacitive performances of the battery-type electrodes. The same sort of the Ni-based ternary metal oxides synthesized with and without adding Ni precursor in hydrothermal solution present very different morphologies and electrocapacitive features, indicating the different amounts and sources of Ni ions play important roles on the growth of the Ni-based metal oxides. The battery-supercapacitor hybrid device composed of the nickel cobalt molybdenum oxide electrode prepared with Ni precursor and the nickel cobalt copper oxide electrode prepared without Ni precursor respectively show areal capacitances of 126.2 and 917.3 mF/cm2 corresponding to the area capacities of 63.1 and 382.2 mAh/cm2, voltage windows of 1.8 and 1.5 V, as well as the maximum energy density of 21.9 Wh/kg at power density of 3.45 W/kg and the maximum energy density of 0.70 Wh/kg at power density of 13.38 W/kg. This work clarifies the function of Ni foam and Ni precursor in the hydrothermal solution for synthesizing Ni-based metal oxides and provide novel synthesizing concept to design efficient materials for energy storage devices.

ВЛИЯНИЕ ПЕРИНАТАЛЬНОГО ВОЗДЕЙСТВИЯ КОБАЛЬТА НА ОБМЕН ЖЕЛЕЗА, МЕДИ, МАРГАНЦА И ЦИНКА В ОРГАНИЗМЕ НЕЗРЕЛЫХ ICR МЫШЕЙ

ВЛИЯНИЕ ПЕРИНАТАЛЬНОГО ВОЗДЕЙСТВИЯ КОБАЛЬТА НА ОБМЕН ЖЕЛЕЗА, МЕДИ, МАРГАНЦА И ЦИНКА В ОРГАНИЗМЕ НЕЗРЕЛЫХ ICR МЫШЕЙ