Effects of Fe2O3 addition (2-20 wt%) with 1 h mechanical activation on redox reactions of Co3O4 were studied by TG/DSC, SEM, and XRD analyses. The results showed that a Fe2O3 addition from 2 to 15 wt% increases the oxygen release from 1.4 to 3.4 wt% and decreases the reduction onset temperature from 1030 to 960 °C, while it increases the oxygen uptake value and re-oxidation onset temperature re...

Cobalt oxide (Co3O4) nanoparticleshave been synthesized by hydrothermal method using mixture of cobalt(II)chloride, Triton X-100 and KOH in an autoclave at 180 °C for 6 h followed by heating at 400 ºC for 3 h in air. The product have been characterized by Fourier transform infrared (FT-IR), UV-Vis spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission ...

We fabricated self-standing films of cellulose nanocrystals (CNC) and electrospun composite fibers with CNC and polyvinyl alcohol both with magnetic properties arising from cobalt iron oxide nanoparticles in the CNC matrix. Aqueous dispersions of cobalt-iron oxide nanoparticles (10–80 nm diameter) and CNCs (ca. 150 nm length) were used as precursor systems for the films and composite fibers. Th...

A cobalamin (Cbl) cofactor in corrinoid iron-sulfur protein (CoFeSP) is the primary methyl group donor and acceptor in biological carbon oxide conversion along the reductive acetyl-CoA pathway. Changes of the axial coordination of the cobalt ion within the corrin macrocycle upon redox transitions in aqua-, methyl-, and cyano-Cbl bound to CoFeSP or in solution were studied using X-ray absorption...

This work proposes a new method for Co(II) determination based on the use of the triblock copolymer as micellar medium instead of chloroform. The proposed strategy is environmental friendly because the copolymer is biodegradable and nontoxic. The method is based on the formation of a cobalt-1-nitroso-2-naphthol complex, in the micellar triblock copolymer compound solution constituted by polyeth...

Motivated by the recent discovery of the cobalt oxide superconductors, we calculate the temperature dependence of the upper critical field on a triangular lattice. Using the lattice version of the Gor’kov equations we investigate how the applied magnetic field affects singlet and triplet types of superconductivity. We show that in a wide range of model parameters not only Zeeman coupling, but a...

We prepared a composite electrode structure consisting of copper nanofiber-networked cobalt oxide (CuNFs@CoOx). The copper nanofibers (CuNFs) were fabricated on a substrate with formation of a network structure, which may have potential for improving electron percolation and retarding film deformation during the discharging/charging process over the electroactive cobalt oxide. Compared to bare ...

A change in the electronic spin state of the surfaces relevant to Li (de)intercalation of nanosized stoichiometric lithium cobalt oxide LiCo(III)O(2) from low-spin to intermediate and high spin is observed for the first time. These surfaces are the ones that are relevant for Li (de)intercalation. From density functional theory calculations with a Hubbard U correction, the surface energies of th...

A high ZT of 0.11 at room temperature was realized in layered cobalt oxide by substitution heavy atomic mass Ba.