CuCo2O4 Nanowires Research Articles

RETRACTED: Hatshan et al. Advanced Binder-Free Electrode Based on CuCo2O4 Nanowires Coated with Polypyrrole Layer as a High-Performance Nonenzymatic Glucose Sensing Platform. Coatings 2021, 11, 1462

The Coatings Editorial Office retracts the article entitled “Advanced Binder-Free Electrode Based on CuCo2O4 Nanowires Coated with a Polypyrrole Layer as a High-Performance Nonenzymatic Glucose Sensing Platform” [...]

3D Nanoflower-like and core-shell structured heterogeneous CuCo2O4@CuCo2S4@Ni(OH)2 electrode materials for high-performance asymmetric supercapacitor

The planning and synthesis of nanocomposite materials with reasonable core-shell heterostructure are of great significance in enhancing the energy density, structural stability as well as long cycle life of asymmetric supercapacitors. We have successfully prepared CuCo2O4@CuCo2S4@Ni(OH)2 core-shell 3D nanoflower array electrode material, resulting in outstanding performance of the assembled supercapacitor. Firstly, CuCo2O4 (CuC) nanowires are grown directly on nickel foam (NF) through hydrothermal and calcination reactions, followed by the formation of heterogeneous CuCo2O4@CuCo2S4 (CuC@CuS) nanoflowers via a hydrothermal reaction by using Na2S·9H2O as a vulcanizing agent. Finally, CuCo2O4@CuCo2S4@Ni(OH)2 electrode material is obtained via the electrodeposition method under a constant voltage. The prepared electrode material is composed of conductive CuC@CuS nanoflowers as the core and deposited Ni(OH)2 nanosheets as the shell, which effectively promotes ion diffusion, increases the reactive area and thereby enhances the electrochemical performance. Impressively, the composite electrode CuC@CuS@Ni(OH)2/NF material achieves an exciting high capacitance of 3753.6 F g−1 (1 A g−1), and the cycle stability is reduced by only 7.1 % after 10,000 cycle tests in the standard three-electrode system. Furthermore, the asymmetric supercapacitor (ASC) device composed of activated carbon (AC) and CuC@CuS@Ni(OH)2 exhibits 729.75 W kg−1 power density under 59.11 Wh kg−1 energy density. The aforementioned findings demonstrate that the CuC@CuS@Ni(OH)2 nanoflower array is a very potential energy storage material.

Hierarchical three-dimensional nanoflower-like CuCo2O4@CuCo2S4@Co(OH)2 core-shell composites as supercapacitor electrode materials with ultrahigh specific capacitances

Here, we prepare three-dimensional nanoflower-shaped CuCo2O4@CuCo2S4@Co(OH)2 core–shell materials on nickel foam (NF). CuCo2O4 (CuC) nanowire arrays and CuCo2S4 (CuS) nanosheets are grown directly on NF as the core through routine hydrothermal and high-temperature calcination methods and Co(OH)2 (CH) small nanosheets deposited on CuC@CuS nanoflowers via the potentiostatic deposition for 15 mins. Due to its distinctive structure and the synergistic effect between multiple components of CuCo2O4@CuCo2S4@Co(OH)2, the electrode has a fantastic specific capacitance (Cs, 4075F/g) under the current density of 1 A/g and satisfying cyclic stability (88.4 % capacitance retention and 84.6 % coulomb efficiency after 10,000 cycles). Additionally, an asymmetric supercapacitor (ASC) device equipped with CuC@CuS@CH-15/NF as a positive and active carbon (AC) electrode as a negative electrode can work steadily at 0–1.6 V. The ASC device can offer an excellent energy density (E, Wh kg−1) of 232.02 Wh kg−1 at a high-power density of 2879.8 W kg−1 (P, W kg−1) and an unexpected cycle stability (84.2 % of the original Cs and 81.7 % of coulombic efficiency after 10,000 repeated GCD tests), which far surpasses other ASCs of the same type. These results guide to enhancement of the electrochemical properties of cobalt-based oxides/sulfides@Co(OH)2 as the positive electrode for supercapacitors.

Enhanced electrochemical performance of CuCo2O4 nanowire arrays based solid-state symmetric supercapacitor by K3[Fe(CN)6] redox additive electrolyte

The redox additive in an aqueous gel electrolyte is reported as one of the efficient methods to improve the electrochemical supercapacitor performance. Here, we report the role of redox additive, potassium ferricyanide((K3[Fe(CN)6]), referred to as KFCN) for improving the electrochemical performance of binder-free, CuCo2O4 (CCO) nanowire arrays (NWs) based solid state symmetric supercapacitors (SSCs). The crystal structure and morphology of prepared CCO films are confirmed by X-ray diffraction (XRD) and field emission-transmission electron microscopy (FE-TEM). The elemental composition of CCO films is estimated as Cu0.5Co2.77O3.82 via energy-dispersive X-ray spectroscopy (EDS) analysis. Surprisingly, the areal capacitance (or energy density at 5 mAcm−2) is significantly improved from 0.58 F cm−2 (or 0.016 mWh cm−2) to 10.5 F cm−2 (or 0.296 mWh cm−2), respectively, after the addition of KFCN to aqueous KOH electrolyte, as compared to bare KOH. Furthermore, CCO exhibits decent cyclic stability with 90 % capacitance retention up to 5000 CV cycles at the scan rate of 100 mV s−1. Moreover, 2-terminal CCO NWs-based SSCs, employed with PVA-KOH-KFCN gel electrolyte, demonstrate a wider potential window of −0.9 to 0.9 V (1.8 V) with a 7-fold increase of energy density from 9.1 to 65 Wh kg−1, as compared with that of PVA-KOH gel electrolyte. As practical validation, the operation of Red-LED for 3 min is demonstrated with PVA-KOH-KFCN gel-based SSC, manifesting that adding redox substance in aqueous electrolytes is one of the promising strategies for portable and wearable energy storage systems.

In-situ growing nanowires on biomass corn pods as free-standing electrodes with low surface reaction barrier for Li-, Al-, and Na-ion batteries

Biomass materials have received extensive attention for energy-storage due to low cost and specific structures. Here, a cost-effective carbonaceous material is prepared from biomass corn pod which is commonly considered as a waste, then CuCo2O4 nanowires are in-situ grown on the surface to form a three-dimensional free-standing electrode for several types of secondary batteries. The porous nanowires accommodate the volumetric change, which is beneficial for the stability; and low surface reaction barrier of the composite is verified by using galvanostatic intermittent titration technique (GITT) analysis. When using as a Li-ion battery anode, the CuCo2O4 nanowires/corn pod displays a capacity of 887 mAh/g after 250 cycles at 0.2 A/g, and the Coulombic efficiency exceeds 99.7 %. Under −10 °C and 45 °C, the capacities remain 726 and 700 mAh/g after 120 cycles, respectively. High rate-performance is achievable after three rounds of measurements. The low-cost free-standing electrode is also suitable for different battery types, displaying high performances as Al-ion battery cathode and Na-ion battery anode, which indicate a potential for engineering high-valuable energy-storage systems.

Electrospun Hollow Carbon Nanofibers Decorated with CuCo2O4 Nanowires for Oxygen Evolution Reaction

In recent years, spinel-type structural cobalt salts (NiCo2O4, CuCo2O4, etc.) have been widely used electrocatalysis because of their superior properties such as large crustal reserves, low cost, environmental friendliness, high electrochemical activity, abundant oxidation valence, and stable chemical properties. In this paper, hollow carbon nanofibers loaded CuCo2O4 nanowires (CuCo2O4@CNFs) were prepared by electrospinning technique and solvothermal method. The CuCo2O4@CNFs exhibit enhances electrocatalytic activity for oxygen evolution reaction (OER), requiring an overpotential of 273 mV in a 1.0 M KOH solution to achieve a current density of 10 mA cm−2. In addition, the overpotential remained almost constant after 3000 cycles of voltammetry measurements. The enhanced electrocatalytic activity may be attributed to the unique one-dimensional hollow nanostructure of CNFs and high dispersion of CuCo2O4 nanowires, which enhanced the charge transfer and improved the diffusion of the electrolyte ions at the surface.

Growth of uniform CuCo2O4 porous nanosheets and nanowires for high-performance hybrid supercapacitors

In this work, uniform CuCo2O4 nanowires (CCO-NWs) and nanosheets (CCO-NSs) were directly grown on the stainless-steel foil via a hydrothermal process with a post calcination treatment in air, and powdered CuCo2O4 materials were obtained once they were peeled off from the stainless-steel substrate. These NWs- and NSs-based powders possessed a huge specific surface area and mesoporous feature. After electrochemical tests, it was found that the CCO-NWs delivered a capacity of 299.12 C g−1 and CCO-NSs could exhibit a capacity of up to 332.18 C g−1. A hybrid supercapacitor (HSC) was assembled with activated carbon (AC) as anode to evaluate the practical applications of CuCo2O4 in energy storage. The CCO-NWs//AC HSC exhibited an energy density of 36.16 W h kg−1 at 1.01 kW kg−1, and as for the CCO-NSs//AC HSC, it delivered 38.46 W h kg−1 at the power density of 1.03 kW kg−1. Both HSCs showed excellent cycling performance over 5000 cycles at 6 A g−1. The superior electrochemical performance of CuCo2O4 NWs and NSs indicates that the battery-type CuCo2O4 electrode materials can serve as advanced cathode for high-performance supercapacitors, and the simple synthetic method can be extended to the preparation of other transition metal oxides (TMOs)-based electrode materials with uniform structure and impressive electrochemical properties.

Construction of Hierarchical CuCo2O4-Ni(OH)2 Core-Shell Nanowire Arrays for High-Performance Pseudocapacitors

The hierarchical CuCo2O4-Ni(OH)2 core-shell nanowire arrays on Ni foam were fabricated using facile and cost-effective two-step hydrothermal synthesis. The growth of CuCo2O4 nanowires was developed on Ni foam as the apposite basis of the conductive scaffold, and the ultrathin Ni(OH)2 nanowires were subsequently immobilized to form CuCo2O4-Ni(OH)2 core-shell nanowire arrays (NWAs). The prepared materials were further characterized in structural, morphological, and electrochemical properties. The obtained CuCo2O4-Ni(OH)2 pseudocapacitor electrode, incorporated by unique core-shell heterostructures nanowire arrays, exhibited great specific capacitance of 1201.67 F g-1 at 1 mA g-1, which is much higher than pristine CuCo2O4 nanowire of 638.89 F g-1 at 1 mA g-1. Simultaneously, it also has a high power density of 5.56 kW kg-1 at an energy density of 73.33 Wh kg-1 and good long-term cycling performance (~84 capacitance retention after 1000 cycles). The improved morphological and structural properties have substantiated the CuCo2O4-Ni(OH)2 core-shell nanowire arrays properties owing to higher surface active area and richer redox activity for boosting the electrochemical properties.

Pt deposited on sea urchin-like CuCo2O4 nanowires: Preparation, the excellent peroxidase-like activity and the colorimetric detection of sulfide ions

Detecting of sulfur ions (S2-) in environment is critical to human health. In this work, a fast and convenient colorimetric sensing platform for S2- was developed. In detail, Pt deposited on sea urchin-like CuCo2O4 nanostructures (Pt/CuCo2O4) was synthesized and demonstrated to possess enhanced peroxidase-like performance, similar to the natural horseradish peroxidase (HRP). Pt/CuCo2O4 can catalyze colorless 3, 3, 5, 5-Tetramethylbenzidine (TMB) to be oxidized by H2O2 into a blue product (oxTMB). When the above system encounters sulfur ions (S2-), the peroxidase-like activity of Pt/CuCo2O4 is inhibited, accompanied with the color change of reaction solutions. On this basis, a colorimetric sensing platform for S2- can be established. Kinetic experiments verified Pt/CuCo2O4 possessed a higher affinity with substrate than that of HPR. The excellent peroxidase-like performance of Pt/CuCo2O4 was attributed to two active species including hydroxyl radical (•OH) and superoxide radical (•O2-) in the catalytic process. The linear range of the proposed sensing platform for S2- was 0.5–10 μM as well as the low limit of detection is 85.9 nM, much lower than the World Health Organization regulations. The sensing platform had been successfully applied to the detection of S2- in tap water and lake water, which provided a convenient method for detecting S2- in wastewater.

RETRACTED: Advanced Binder-Free Electrode Based on CuCo2O4 Nanowires Coated with Polypyrrole Layer as a High-Performance Nonenzymatic Glucose Sensing Platform

In this work, the CuCo2O4 nanowires (CuCo2O4 NWs) were grown on carbon cloth electrode (CCE) and then coated with polypyrrole (pPy) layer (CuCo2O4 NWs-pPy@CCE). The morphology and structure characterization of as-prepared CuCo2O4 NWs-pPy@CCE were carried out using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), field-emission scanning electron microscope (FESEM), thermogravimetric analysis (TGA), and transmission electron microscope (TEM). The CuCo2O4 NWs-pPy@CCE was applied directly as an electrocatalyst toward nonenzymatic glucose oxidation. Due to the advantages of this 3D structure, it offer high availability to the analyte/electrolyte, abundant electrochemical-active sites, and high stability and conductivity. As a glucose sensor, the CuCo2O4 NWs-pPy@CCE shows wide linear range (0.01 to 21.3 mM), excellent sensitivity (4.41 μA μM−1 cm−2), good selectivity, low detection limit (0.2 μM), and rapid response time (<1 s) toward glucose detection. Furthermore, the designed sensor shows a great ability in detection of glucose in biological real samples.

Flower-Like Nanostructured CuCo2O4 Grown on the Surface of Conductively-Treated Filter Paper as a Flexible Anode for Lithium-Ion Batteries

We synthesized a flexible lithium-ion battery (LIB) anode with a flower-like CuCo2O4 nanostructure grown on the surface of conductively-treated filter paper. The filter paper, made of cotton fibers, has good flexibility, but its poor conductivity limits its application in flexible electrodes. An Ni coating by magnetron sputtering can significantly improve its conductivity, which enables it to be used as a substrate for flexible electrodes. The flower-like CuCo2O4 nanostructure is assembled from CuCo2O4 nanowires with a diameter of 50 nm, while the CuCo2O4 nanowires are assembled from CuCo2O4 nanoparticles with a size of 10–20 nm. The gap between the stacked CuCo2O4 nanoparticles causes the porous structure of the CuCo2O4 nanowires. The high theoretical capacity of CuCo2O4, the porous structure of the CuCo2O4 nanowires, and the tiny CuCo2O4 nanoparticles lead to the excellent electrochemical performance of the CuCo2O4 flower-like nanostructure. It maintains capacity very well during cycling and delivers a high capacity of 989 mAh g−1 at a current density of 100 mA g−1. As a flexible LIB anode, the composite with the flower-like CuCo2O4 nanostructure grown on the surface of conductively-treated filter paper delivers a stable capacity of 544 mAh g−1 at a current density of 100 mA g−1 and a capacity of 304 mAh g−1 at a high current density of 2000 mA g−1. The conductively-treated filter paper substrate can significantly improve the battery property of the hydrothermally-fabricated CuCo2O4.

When Al3+ meets CuCo2O4 nanowire arrays: An enhanced positive electrode for energy storage devices

Abstract Bimetal oxides have superior supercapacitive properties because of synergistic effect, but their applications are usually limited because of low conductivity. Metal cations doping has been a promising method to break the restriction. Here, we first selected CuCo2O4 nanowire arrays with high electrochemical activity as mother bimetal oxides and Al3+ with high electric conductivity as the dopant to investigate the influence of doped amounts on the electrochemical behaviors. With the increase of doped Al3+, the specific capacitance increased at first and then decreased, in accord with the analysis results of the conductivity, capacitive and diffusion-controlled contribution. The sample with the optimal doping amount had the highest capacitive behavior (1871 F g−1 at 1 A g−1) and considerable cycling performance (93% after 8000 cycles at 2 A g−1). A full button cell consisting of anode material (AC) and cathode material (the optimal Al-doping CuCo2O4) exhibited satisfied energy density (65 Wh kg−1) and power density (735 W kg−1) as well as favorable cycling performance (95% retention after 4000 cycles). A LED was successfully powered by the constructed full cell suggested the promising application in future industrial green energy-storage devices of the Al-doping CuCo2O4 nanomaterials.

A novel Fe2O3-decorated N-doped CNT porous composites derived from tubular polypyrrole with excellent rate capability and cycle stability as advanced supercapacitor anode materials

As an advanced anode materials for high-performance asymmetric supercapacitors, the N-doped carbon nanotube (N-CNT) derived from tubular polypyrrole nanotube is decorated with Fe2O3 to produce the mesoporous 3D Fe2O3/N-CNT frameworks. The crystal structures and morphologies of the obtained products are investigated by XRD and FE-SEM. The electrochemical performances are evaluated by cyclic voltammetry, galvanostatic charge-discharge and impedance studies. The obtained Fe2O3/N-CNT composite electrode delivers a maximum specific capacitance of 264 F g−1 at 1 mA cm−2, high rate capability with a capacitance retention of 79% at 10 mA cm−2 and good cycling stability with 84% capacitance loss after 10000 cycles at 7 mA cm−2. The asymmetric Fe2O3/N-CNT//CuCo2O4 nanowires device exhibits at a high energy density 22.8 Wh kg−1 at the power density 216 W kg−1 in 2 M KOH aqueous electrolyte.

Ni–Co–S nanosheets supported by CuCo2O4 nanowires for ultra-high capacitance hybrid supercapacitor electrode

Recently, constructing core-shell arrays directly on conductive substrates is proved as a promising strategy for energy storage devices, due to the abundant active sites and fast electrons transport paths. In this work, we design core-shelled CuCo2O4@Ni–Co–S arrays directly on Ni foam substrate by the hydrothermal and electrodeposition processes. The core-shelled arrays can possess the large accessible surface area, fast charge transfer kinetics and the synergistic effect from both components, leading to better electrochemical performances. Consequently, core-shell CuCo2O4@Ni–Co–S arrays can deliver a high specific capacitance of 12.10 F cm−2 (corresponding to 2897 F g−1 mass specific capacitance), and good cycle stability with 82.5% capacitance retention after 8000 cycles of charging and discharging at 20 mA cm−2. In addition, a battery-supercapacitor hybrid device made of CuCo2O4@Ni–Co–S and activated carbon displays a high energy density of 0.65 mWh cm−2 at 32 mW cm−2 power density, and the capacitance loss less than 20% (~83.6%) after 8000 cycles.

Three-dimensional mesoporous sandwich-like g-C3N4-interconnected CuCo2O4 nanowires arrays as ultrastable anode for fast lithium storage

Inspite of their impressive high theoretical capacity as Lithium-ion batteries (LIBs) anodes, spinel transition-metal oxides (TMOs) suffer serious volume expansion, aggregation and the pulverization of crystal structures during lithiation/delithiation, and this process severely restrict their industrial application. Multi-dimensional morphological engineering of spinel TMO nanostructures is an effective way to solve this issue. In this work, using facile hydrothermal synthetic methods, spinel CuCo2O4 nanowires arrays are synthesized and supported on g-C3N4 nanosheets, thus forming a unique sandwich-like interconnected three-dimensional mesoporous structure containing high amount of void spaces. Addition of g-C3N4 nanosheets to CuCo2O4 nanowire arrays may shorten the Li+ diffusion distance and electron transfer pathway, and may also provide more active sites for Li+ diffusion into electrolyte and buffer for the volume expansion and aggregation of CuCo2O4. As a LIB anode material, CuCo2O4@g-C3N4 shows initial lithiation capacity of 840.6 mAh g−1, and capacity retention of 641.2 mAh g−1 after 60 cycles at the current density of 0.1 A g−1 and 499.2 mAh g−1 after 40 cycles at high current of 1 A g−1, which is significantly better than value of pure CuCo2O4 nanowires. This work affords a new way to tackle the problem of volume expansion of high capacity spinel TMO anode materials using g-C3N4 nanosheets as buffering agent.

CuCo2O4 nanowire arrays wrapped in metal oxide nanosheets as hierarchical multicomponent electrodes for supercapacitors

Herein, we report the rational design and fabrication of multicomponent, hierarchical CuCo2O4 nanowire arrays wrapped with metal oxides (NiO, Co3O4 and MnO2) nanosheets for use in high-performance supercapacitors. Among all the composite electrodes prepared, the CuCo2O4@NiO electrode exhibits the best electrochemical behavior with a high areal capacitance of 2.3 F/cm2 at 2 mA/cm2 and excellent cycling stability. The asymmetric supercapacitor with CuCo2O4@NiO as the positive electrode shows a superior specific capacitance of 124.6 F/g at 1 A/g, exceptional energy density of 38.9 Wh/kg at 750 W/kg, and long cycle life with ∼81.3% capacitance retention after 6000 cycles. The results indicate that the CuCo2O4@NiO electrode shows great potential for high-performance electrochemical energy storage.

Hierarchical CuCo2O4 nanourchin supported by Ni foam with superior electrochemical performance

Three-dimensional (3D) hierarchical CuCo2O4 nanourchin architecture assembled from one-dimensional (1D) porous CuCo2O4 nanowire is successfully fabricated on Ni foam using a facile hydrothermal method followed by thermal treatment. The electrochemical properties of the synthesized nanomaterial have further investigated as the binder-free electrode for supercapacitor. Impressively, the porous CuCo2O4 nanourchin electrode exhibits remarkable pseudocapacitive performance with a high specific capacitance of 1569.9 F g-1 at a current density of 0.6 A g−1 (corresponding to 5.2 F cm-2 at 2 mA cm−2), good rate capability and excellent cycling stability (nearly 98.0% capacitance retention after 4000 cycles at a current density of 3.0 A g−1). Moreover, even at a high current density of 20 A g−1, the CuCo2O4 nanourchin electrode still maintains around 71.1% of the initial capacitance over 10000 cycles. The outstanding pseudocapacitive behaviors are mainly due to its hierarchical structure of the porous CuCo2O4 nanourchin architecture which provides large electroactive surface sites, big electrolyte infiltrate area, high-electron/ion-transfer rate and good structure stability. Moreover, an asymmetric supercapacitor based on CuCo2O4 nanourchin on Ni foam as positive electrode and activated carbon (AC) as negative electrode is successfully assembled to further evaluate the electrochemical properties for practical applications. Remarkably, the CuCo2O4//AC asymmetric device has demonstrated a high energy density of 23.9 Wh kg−1 at a power density of 593.2 W kg−1 and excellent cycling stability (91.5% capacitance retention after 2000 cycles).

CoMoO4 nanoplates decorated CuCo2O4 nanowires as advanced electrodes for high-performance hybrid supercapacitors

Hierarchical CuCo2O4@CoMoO4 nanowire/nanoplate hybrid nanostructures are successfully grown on Ni foam via simple methods involving hydrothermal and post-annealing treatment. The hybrid electrode exhibits a high areal capacity of 500 μAh/cm2 at 2 mA/cm2 and a good cycling stability with 84.1% retention over 2000 cycles at 20 mA/cm2. The assembled hybrid supercapacitor device based on CuCo2O4@CoMoO4 and activated carbon as the positive and negative electrodes achieves a maximum energy density of 49 Wh/kg at a power density of 318 W/kg, showing the great potential of this hybrid materials as advanced electrodes for energy storage devices.

A high performance asymmetric supercapacitor based on in situ prepared CuCo2O4 nanowires and PPy nanoparticles on a two-ply carbon nanotube yarn.

One-dimensional supercapacitors (SCs) are of great interest for future wearable electronics, but improvement in both high capacitance and high flexibility is still a challenge. Herein, we fabricate a high performance yarn asymmetric SC (ASC) using in situ prepared CuCo2O4 nanowires and polypyrrole (PPy) nanoparticles on the surface of a two-ply carbon nanotube (CNT) yarn. The parallel-shaped yarn ASC not only shows outstanding redox pseudocapacitance, including a high areal capacitance (59.55 mF cm-2), specific energy density (20 μW h cm-2) and power density (5.115 mW cm-2), but also exhibits good flexibility because of its well maintained capacitance during repeated dynamic bending states. The capacitance retention still remains 80.1% under 8000 cycles, suggesting relatively good reversibility and stability.

3D free-standing hierarchical CuCo2O4 nanowire cathodes for rechargeable lithium-oxygen batteries.

A carbon and binder-free cathode for use in Li-O2 cells which is based on free-standing CuCo2O4 nanowires supported on a nickel foam was synthesized by an efficient hydrothermal method. The resulting hierarchical porous and umbrella structures of the hybrid CuCo2O4@Ni foam cathodes present an excellent rate capability and cycle performance.