82 Results Found

For a long time, transition metal oxide systems have been considered well explored materials in heterogeneous catalysis. Amongst, the spinel-type oxides, materials such as cobaltites (Co₃O₄) received significant attention, owing to their use in many...

The electrochemical properties of the dysprosium-doped strontium cobaltite SDC (Sr_0.8Dy_0.2CoO_3−δ) were evaluated for possible application as pseudocapacitor electrode materials. Dense perovskite SDC ceramics were prepared using standard s...

Na₀.₈₉Co_0.90Me_0.10O₂ (Me = Cr, Ni, Mo, W, Pb, and Bi) ceramic samples were prepared using a solid-state reaction method, and their crystal structure, microstructure, and electrical, thermal, and thermoelectric properties were investigated. The effect...

Introducing new inexpensive materials for supercapacitors application with high energy density and stability, is the current research challenge. In this work, Silver doped carbon xerogels have been synthesized via a simple sol-gel method. The silver...

A facile hydrothermal method has been developed to prepare a nickel cobaltite/multiwalled carbon nanotubes (NiCo₂O₄/MWCNTs) composite. The structure and morphology of NiCo₂O₄/MWCNTs were tested by X-ray diffraction, X-ray photoelectron spectroscopy,...

In-situ investigations of structural transitions during the thermal-oxidative event of mixed-metal spinel oxide precursors, the so-called nickel- (NCO) and zinc-containing (ZCO) cobaltite spinel precursors, were investigated to understand the formati...

Cerium-doped zinc cobaltite spinel thin films, $\mathrm{Z}\mathrm{n}{\mathrm{C}\mathrm{e}}_{\mathrm{x}}{\mathrm{C}\mathrm{o}}_{2-\mathrm{x}}{\mathrm{O}}_4 (0.00\le \mathrm{x}\le 0.05)$, were synthesized via spray pyrolysis, and their structural, morphological, optical, and electrical properties were analyzed. X-ray diffraction (XRD) confirmed...

In this paper, we prepared mesoporous nickel cobaltite (NiCo₂O₄) nanostructures with multi-morphologies by simple solvothermal and subsequent heat treatment. By adjusting the solvent type, mesoporous NiCo₂O₄ nanoparticles, nanorods, nanowires, and mi...

This work uses a hole-transporting copper cobaltite/copper oxide nanocomposite to fabricate carbon-based MAPbI₃ PSCs. The copper cobaltite/copper oxide HTM-based PSC results show the highest power conversion efficiency (PCE = 7.32%) compared with an...

In this work, nanostructured (La_0.6Sr_0.4)_0.99CoO₃ (LSC)-Ce_0.8Gd_0.2O_1.9 (CGO) core-shell particles were prepared by precipitating CGO nanoparticles on the surface of LSC particles under hydrothermal conditions. The as-prepared core-shell particles wer...

Cobalt (Co) is a critical metal for the energy transition, and its enrichment mechanisms are crucial for resource assessment. Here, we investigate Co mineralization in the Qiaoxiahala Fe–Cu–Au deposit through integrated mineralogical, geo...

Advanced oxidation processes (AOPs) are effective ways to degrade refractory organic contaminants, relying on the generation of inorganic radicals (e.g., ^•OH and SO₄^•−). Herein, a novel AOP with organic radicals (R-O^•) was report...

Solar-driven evaporation technology is often used in areas with limited access to clean water, as it provides a low-cost and sustainable method of water purification. Avoiding salt accumulation is still a substantial challenge for continuous desalina...

The electrical properties of solution-processed spinel nickel cobaltite (NiCo₂O₄) nanoparticulated-based metal oxide hole transporting layers are investigated using conductivity and Hall effect measurements. The mechanism of electrical conductivity o...

Mixed conducting cobaltites PrBaCo_2−xFe_xO_6−δ (x = 0–0.6) with a double perovskite structure are promising materials for ceramic semi-permeable membranes for oxygen separation and purification due to their fast oxygen exchange...

Increasingly stringent emission regulations in combustion systems drive the demand for robust, cost-effective gas sensors capable of operating under harsh, high-temperature conditions. Thermoelectric ceramic gas sensors represent a promising approach...

Located 30 km south–southeast of Kabul in Logar province, Aynak is the largest and best-known copper orebody in Afghanistan. The deposit is hosted by the Loy Khwar Formation, a Neoproterozoic–Cambrian metasedimentary sequence of dolomite...

Zinc cobaltite (ZnCo₂O₄) is a ternary metal oxide found in spinel with promising properties for various applications. Optimizing its catalytic activity requires an understanding of its electrochemical behavior. The electrochemical properties of ZnCo₂...

The application of double perovskite cobaltites BaLnCo₂O_6−δ (Ln = lanthanide element) in electrochemical devices for energy conversion requires control of their properties at operating conditions. This work presents a study of a series of...

High-performance electrode materials are fundamental to improving supercapacitor performance, serving as key factors in developing devices with high energy density, high power density, and excellent cyclic stability. Non-stoichiometric spinels with p...

Supercapacitors have played an important role in electrochemical energy storage. Recently, researchers have found many effective methods to improve electrode materials with more robust performances through the increasing volume of scientific publicat...

Using the solid-state reactions method Na_0.55(Co,M)O₂ (M = Cr, Ni, Zn, W, and Bi) ceramics were prepared and their crystal structure, microstructure, electrophysical, thermophysical, and thermoelectric properties were studied. Doping of Na_0.55CoO₂ by...

Misfit layered compounds (MLCs) have been studied in the literature for the last 40 years. They are generally made of an alternating sequence of two monolayers, a distorted rocksalt structure, and a hexagonal layered compound. In a typical MLC, the c...

The traditional solid-state reaction method was employed to synthesize bulk calcium cobaltite (Ca349/Ca₃Co₄O₉) ceramics via ball milling the precursor mixture. The samples were compacted using conventional sintering (CS) and spark plasma sintering (S...

In this work, we investigated the influence of oxygen plasma on the growth of nickel cobaltite (NiCo₂O₄) thin films compared to growth in a molecular oxygen atmosphere. The films were grown on MgO(001), MgAl₂O₄(001) and SrTiO₃(001) substrates by oxyg...

Nickel-based catalysts have been widely recognized as highly promising electrocatalysts for oxidation. Herein, we designed a catalyst surface based on iron oxide electrodeposited on NiCo₂O₄ spinel oxide. Nickel foam was used as a support for the prep...

Lanthanum perovskites are promising candidates to replace platinum group metal (PGM), especially regarding catalytic oxidation reactions. We have prepared thin catalytic coatings of Sr and Ag doped lanthanum perovskite by using the cathodic co-sputte...

Oxygen stoichiometry critically governs the phase stability and physical properties of transition-metal oxides, yet a unified understanding of how oxygen-stoichiometry-driven phase reconstruction underlies the cooperative evolution of multiple physic...

The perovskite oxide SrCoO_3−x is a promising oxygen electrocatalyst for renewable energy storage and conversion technologies. Here, A, B-site Co-doped perovskite Sr_0.5Ba_0.5Co_0.95Mn_0.05O_3−x nanoparticles were rationally designed and synthe...

As cobalt (Co) has been the most useful element for activating Oxone to generate SO₄^•−, this study aims to develop a hierarchical catalyst with nanoscale functionality and macroscale convenience by decorating nanoscale Co-based oxides on m...

The structural, magnetic, electrical, and dilatation properties of the rare-earth NdCoO₃ and SmCoO₃ cobaltites were investigated. Their comparative analysis was carried out and the effect of multiplicity fluctuations on physical properties of the stu...

This paper presents an experimental approach to maximizing the voltage generated by Na_xCoO₂ and improving the overall efficiency of the p-type thermoelectric leg by doping with Na up to x = 0.88. Two samples with different geometries were tested, eac...

The Na_0.5Co_0.9Cu_0.1O₂ thick film with the same thermoelectric performance as a Na_0.5CoO₂ bulk was formed on an alumina substrate by the screen-printing process. The power factor exceeded 0.3 mW/K²m, with the resistivity of 3.8 mΩcm and the ther...

This work further explores the possibilities for designing the high-temperature electrical performance of the thermoelectric Ca₃Co₄O₉ phase, by a composite approach involving separate metallic iron and nickel particles additions, and by employing two...

The aim of this work was to study cyclic stress–strain deformation behavior of LaCoO₃ as a function of loading and heating history. The ferroelastic hysteretic deformation of LaCoO₃ at different stresses and temperatures was characterized using effec...

In this work, we prepared spinel-type NiCo₂O₄ (NCO) nanopowders as a low-cost and sensitive electrochemical sensor for nonenzymatic glucose detection. A facile and simple chemical bath method to synthesize the NCO nanopowders is demonstrated. The eff...

Thin films of the catalytically interesting ternary and quaternary perovskites GdCoO₃ and Gd_0.9Ca_0.1CoO₃ are fabricated by atomic layer deposition using metal β-diketonates and ozone as precursors. The resulting thin films are amorphous as depos...

Aliovalent substitutions in Ca₃Co₄O₉ often result in complex effects on the electrical properties and the solubility, and impact of the substituting cation also depends largely on the preparation and processing method. It is also well-known that the...

Along with the soaring demands for all-solid-state thin-film lithium-ion batteries, the problem of their energy density rise becomes very acute. The solution to this problem can be found in development of 3D batteries. The present work deals with the...

It is well-known that the electrical properties of the Ca₃Co₄O₉ thermoelectric (TE) compound are strongly influenced by the valence of the substituting cation, while its solubility and “functional” impact depend largely on the preparation...

Development of new functional materials with improved characteristics for solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs) is one of the most important tasks of modern materials science. High electrocatalytic activity in oxyg...

The high efficiency of solid oxide fuel cells with La_0.8Sr_0.2MnO_3−δ (LSM) cathodes working in the range of 800–1000 °C, rapidly decreases below 800 °C. The goal of this study is to improve the properties of LSM cathodes work...

In this paper, we report on nanodisc-shaped MgCo₂O₄ wrapped with ZnS, achieved using the sol–gel-assisted hydrothermal method. This enhances the electrochemical performance, with the electrode delivering superior supercapacitive performance compared...

Perovskites are promising alternative catalysts for oxidation reactions due to their lower cost compared to noble metals, and their greater thermal stability. The catalytic oxidation of CO is essential in order to control CO emissions in a series of...

Spinel ZnCo₂O₄ nanoparticles were synthesized by means of the microwave-assisted colloidal method. A solution containing ethanol, Co-nitrate, Zn-nitrate, and dodecylamine was stirred for 24 h and evaporated by a microwave oven. The resulting solid ma...

In this study, Ca_3−xAg_xCo₄O₉ ceramics were synthesized by the sol–gel method combined with spontaneous combustion and cold isostatic pressing. The Ca_3−xAg_xCo₄O₉ ceramics were characterized via X-ray diffraction and scanning electron...

This paper reports a novel composite-based processing route for improving the electrical performance of Ca₃Co₄O₉ thermoelectric (TE) ceramics. The approach involves the addition of metallic Co, acting as a pore filler on oxidation, and considers two...

Currently, wastewater containing high urea levels poses a significant risk to human health. Else, electrocatalytic methodologies have the potential to transform urea present in urea-rich wastewater into hydrogen, thereby contributing towards environm...

Differential scanning calorimetry studies of the complex oxide YBaCo₂O_6-δ (YBC), combined with the literature data, allowed outlining the phase behavior of YBC depending on the oxygen content and temperature between 298 K and 773 K. The oxygen...

Spinel-type cobalt oxide is a highly active catalyst for oxidation reactions owing to its remarkable redox properties, although it generally exhibits poor mechanical, textural and structural properties. Supporting this material on a porous alumina ca...