ZnCo2O4

In this study, we developed a novel p-n/Z-scheme heterojunction photocatalyst, ZnCo2 O4 /BiOBr (ZCo/BB), through a straightforward and safe hydrothermal-calcination-solvent thermal method. The composite photocatalyst demonstrated exceptional photocatalytic efficacy, particularly when the mass ratio of ZnCo2 O4 was 25% (referred to as 25% ZCo/BB). Structural characterization and electrochemical analysis revealed that 25% ZCo/BB exhibited a larger specific surface area and a faster electron transfer rate. Under visible light exposure for 30 min, methylene blue (MB) degradation reached 92%, and the reaction rate constants were 8...

In this article, binary oxide ZnCo2 O4 nanoparticles (NPs) have been developed on reduced graphene oxide surface by simple reflux condensation method. The physicochemical characteristics of the synthesized nanocomposite were computed using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and UV-Visible spectroscopy. The average size of ZnCo2 O4 NPs is found to be about 9 nm. The synthesized nanocomposite was found to be an extremely efficient catalyst for reduction of 4-nitrophenol (4-NP) to produce 4-aminophenol (4-AP) and it is exhibited that about 98% 4-nitrophenol can be reduced in only 20 min...

Dealing with overcoming the sluggishness of the oxygen evolution reaction (OER), the urea oxidation reaction (UOR) existed. ZnCo2O4, an excellent OER electrocatalyst, its application towards UOR is studied with surface-grown polydopamine (PDA). ZnCo2O4@PDA is produced over the surface of nickel foam by hydrothermal method followed by self-polymerization of dopamine hydrochloride. Dopamine hydrochloride was varied in solution mixture to study the optimal growth of PDA necessary to enhance electrochemical activity...

The development of productive catalysts for oxygen evolution reaction (OER) remains a major challenge that requires significant progress in both mechanism and material design. Conventionally, the thermodynamic barrier of the lattice oxidation mechanism (LOM) is lower than that of absorbate evolution mechanism (AEM) because the former could bypass certain limitations. However, it remains a challenging task to control the OER pathway from the AEM to the LOM by taking advantage of the intrinsic properties of catalyst...

ZnCo2O4 has been attracted wide research attention as a promising anode material for lithium-ion batteries (LIBs) in recent years based on its high theoretical specific capacity, low toxicity as well as stable chemical properties. However, the further large-scale application of pristine ZnCo2O4 anode have been impeded because of its undesirable Li+ ion conductivity, low electronic conductivity, and finite stability of electrolytes at high potentials. Recently, optimizing micro/nano structure, modified with carbonaceous materials, incorporating with metal oxides and constructing binder-free structure on conductive substrate for ZnCo2O4-based materials have been verified as promising effective routes for solving the above problems...

Scientific research is being compelled to develop highly efficient and cost-effective energy-storing devices such as supercapacitors (SCs). The practical use of SC devices is hindered by their low energy density and poor rate capability due to the binding agents in fabricating electrodes. Herein, we proposed flower-like highly open-structured binder-free ZnCo2 O4 micro-flowers composed of nanosheets supported in nickel foam (ZnCoO@NF) with improved rate capability up to 91.8% when current varied from 2 to 20 A·g-1 ...

Nitrate (NO 3 - ) as a common pollutant under groundwater causes drinking water safety problems and seriously endangers people's health. Electrochemistry reduction nitrate to ammonia under ambient condition is a green and significant route to reduce the concentration of NO 3 - and produce ammonia (NH 3 ), known as a complement to the Haber-Bosch reaction. Currently, noble-metal electrocatalysts are often used in electrochemical reduction of NO 3 - , but high cost and scarcity limited their application. Herein, three dimensional (3D) flower-like zinc cobaltite (ZnCo 2 O 4 ) electrocatalyst was developed to convert nitrate into ammonia at room temperature...

High energy-density supercapacitors (SCs) with long operating life, cost-effective, and competitive cycling performance is attracted great research attention to competing in the requirements of the modern age. However, despite these benefits, SC hampers inadequate rate-capability and structural deterioration, which primarily affects its commercialization. Herein, ultra-thin two-dimensional (2D) ZnCo2O4 nanosheets are in-situ anchored on the conductive surface of nickel foam (denoted as ZCO@NF) by hydrothermal process...

Nanocavity-enriched Co3O4@ZnCo2O4@NC porous nanowires have been successfully prepared by a two-step annealing process of one-dimensional (1D) coordination polymer precursors. Such unique nanowires with nanocavity-based porous channels can provide a large specific surface area, which allows fast electron/ion transfer and alleviates the volume expansion caused by strain during the charge/discharge processes. While used as the anode material of lithium-ion batteries (LIBs), Co3O4@ZnCo2O4@NC electrodes exhibit outstanding rate capacity and cycling stability, such as a high reversible capacity of 931 mA h g-1 after 50 cycles at a current density of 0...

The ZnCo2O4@NiCo2S4@PPy core-shell nanosheets material is prepared by directly growing leaf-like ZnCo2O4 nanosheets derived from the metal-organic framework (MOF) on Ni foam (NiF) via chemical bath deposition and annealing methods and then combining with NiCo2S4 and PPy via electrodeposition methods. The special core-shell structure formed by MOF-derived ZnCo2O4, NiCo2S4 and PPy creates a bi-interface, which could significantly promote the contact between electrode and electrolyte, provide more active sites and accelerate electron/ion transfer...

Metal-organic framework (MOF)-derived nanoporous carbons (NPCs) and porous metal oxide nanostructures or nanocomposites have gathered considerable interest due to their potential use in supercapacitor (SCs) applications, owing to their precise control over porous architectures, pore volumes, and surface area. Bimetallic MOFs could provide rich redox reactions deriving from improved charge transfer between different metal ions, so their supercapacitor performance could be further greatly enhanced. In this study, "One-for-All" strategy is adopted to synthesize both positive and negative electrodes for hybrid asymmetric SCs (ASCs) from a single bimetallic MOF...

Spinel ZnCo2O4/ZnO/C hierarchically porous structures were successfully synthesized by two-step annealing of cyanide-bridged coordination polymer precursors. Such hierarchically porous structures exhibit a regular cube structure and provide a large surface area, which provides excellent charge transport kinetics by promoting the charge transfer into the inside of the electrode materials. When used as the anode material of lithium ion batteries, the spinel ZnCo2O4/ZnO/C porous structures exhibit high capacity and excellent cycling stability with a capacity of 1100 mA h g-1 at a current density of 0...

There is an urgent need to develop in situ sensors that monitor the continued release of H2S from biological systems to understand H2S-related pathology and pharmacology. For this purpose, we have developed a molybdenum disulfide supported double-layered zinc cobaltite modified carbon cloth electrode (MoS2-ZnCo2O4-ZnCo2O4) based electrocatalytic sensor. The results of our study suggest that the MoS2-ZnCo2O4-ZnCo2O4 electrode has excellent electrocatalytic ability to oxidize H2S at physiological pH, in a minimized overpotential (+0...

Developing electrode materials with high specific capacitance and excellent stability for energy storage is necessary to solve energy shortage issues. In this work, we prepare ZnCo2O4@CoMoO4 core-shell structures on nickel foam by a simple hydrothermal approach. The as-synthesized products show excellent electrochemical performances. It reveals that the secondary growth of CoMoO4 nanosheets induces many active sites and facilitates rapid ion and electron transmission. In addition, the as-assembled device delivers high energy density, indicating that the as-obtained samples are excellent candidates for future energy storage applications...

Li-CO2 batteries are of great interest among researchers due to their high energy density and utilization of the greenhouse gas CO2 to produce energy. However, several shortcomings have been encountered in the practical applications of Li-CO2 batteries, among which their poor cyclability and high charge overpotential necessary to decompose the highly insulating discharge product (Li2 CO3 ) are the most important. Herein, the spinel zinc cobalt oxide porous nanorods with carbon nanotubes (ZnCo2 O4 @CNTs) composite is employed as a cathode material in Li-CO2 batteries to improve the latter's cycling performance...

In this work, quasi two dimensional spinel ZnCo2O4 (ZCO) nanosheets constituted by ZCO grain with different size were prepared via a facile solvothermal method and followed by a post-treatment. It shows that the small ZCO grain can be obtained by a fast cooling post-treatment. Further, to enhance the conductivity of ZCO, uniform and compact ZCO nanosheets was in-situ grown on reduced graphene oxide (rGO), which was employed as template. When used as anode for lithium ions battery (LIB), rGO@ZCO has a large reversible capacity of 1107...

Multi-shelled hollow metal oxide nanostructures have attracted tremendous attention in energy storage devices owing to their high specific capacity, rate capability and ameliorated cycling performance. Although great progress has been made in synthesizing multi-shelled hollow structures, most methods still depend on tedious template mediated strategies to generate complex interior structures. Herein, we developed a facile universal self-templated approach to synthesize a series of multi-shelled hollow metal oxide spheres with tailored compositions...

The high cost and elemental scarcity of precious metals has triggered a search for non-noble-metal catalysts for the oxygen evolution reaction (OER) process. Herein, with the assistance of metal organic frameworks (MOFs), a core/shell ZnCo2 O4 /ZnO nanoarray with an amorphous carbon protecting layer, grown on carbon fiber, was in situ topologically generated. The resulting catalyst shows much enhanced OER performance under alkaline condition, requiring as low as 279 mV of overpotential to reach 10 mA cm-2 current density...

Advanced sensing materials are in high demand for sensitive, real-time and continuous detection of gas molecules for gas sensors, which have been becoming an effective tool for environmental monitoring and disease diagnosis. Cobalt-containing spinel oxides are promising sensing materials for the gas sensing reaction owing to their element abundance and remarkable activity. Structural and component properties can be modulated to optimize the sensing performances by substituting Co with other transition metals...

A coordination co-precipitation route followed by a calcination process was developed to prepare mixed transition metal oxide microspheres with a yolk-shell structure. ZnCo2O4, NiCo2O4, MnCo2O4, ZnMn2O4 and CoMn2O4 have been successfully fabricated, which demonstrates the universality of this route. As a promising anode for lithium-ion batteries (LIBs), ZnCo2O4 was investigated as a typical example, which showed a remarkable reversible capacity of 1063 mA h g-1 after 50 cycles at a current density of 200 mA g-1 and a good rate capability of 839 mA h g-1 after 200 cycles at a large current density of 900 mA g-1...