The effect of nano Co3O4 addition on the superconducting properties of (Bi, Pb)-2223 system was studied. The samples were prepared by the acetate coprecipitation method. The Co3O4 with different sizes (10-30 nm and 30-50 nm) from x=0.00 to 0.05 was added to Bi1.6Pb0.4Sr2Ca2Cu3Oy(Co3O4)x. Phase analysis by XRD method, microstructural examination by SEM and dc electrical resistivity by four point...

A low cost, durable, and efficient electrocatalyst for oxygen reduction reactions (ORR) is essential for high-performance fuel cells. Here, we fabricated Co3O4 nanoparticles (NPs) anchored on N-doped mesoporous carbon nanofibers (Co3O4/NMCF) by electrospinning combined with the simple heat treatment. Within this composite, carbon nanofibers possess a mesoporous structure, contributed to obtain ...

Spectroscopic ellipsometry and atomic force microscope techniques were employed to analyze optical properties, microstructure and thickness of cobalt oxide thin films deposited on metal substrates by the sol-gel dipping method. The ellipsometric data were conveniently fitted, assuming a stratified structure for the deposited film, which consists of a sublayer native oxide that was coated with a...

Here we proposed a novel architectural design of a ternary MnO2-based electrode - a hierarchical Co3O4@Pt@MnO2 core-shell-shell structure, where the complemental features of the three key components (a well-defined Co3O4 nanowire array on the conductive Ti substrate, an ultrathin layer of small Pt nanoparticles, and a thin layer of MnO2 nanoflakes) are strategically combined into a single entit...

One-dimensional (1D) hierarchical porous nanofibers of Co3O4 possessing of (220) facets on the carbon matrix from human hair (H2@Co3O4) with 20-30 nm in width and 3-5 μm in length are prepared by a facile solvothermal and calcination approach. The well crystallized small Co3O4 particles with the diameter of about 8-12 nm were closely aggregated together in the nanofibers. Electrochemical analys...

Artificial photosynthesis is a very attractive and a desirable way to solve the rising energy demand. In order to harvest energy directly from sunlight catalyst for oxygen reduction and evolution reaction are at the core of key renewable-energy technologies including fuel cells and water splitting. Herein, tungsten oxide-reduced graphene oxide (WO3-rGO), cobalt oxidereduced graphene oxide (Co3O...

A series of novel hierarchical nanoporous microstructures have been synthesized through one-step chemical reduction of micron size Cu2O and Co3O4 particles. By controlling the reduction time, non-porous Cu2O microcubes sequentially transform to nanoporous Cu/Cu2O/Cu dented cubic composites and hollow eightling-like Cu microparticles. The mechanism involved in the complex structural evolution is...

A new concept for preparing hollow metal oxide nanopowders by salt-assisted spray pyrolysis applying nanoscale Kirkendall diffusion is introduced. The composite powders of metal oxide and indecomposable metal salt are prepared by spray pyrolysis. Post-treatment under a reducing atmosphere and subsequent washing using distilled water produce aggregation-free metal nanopowders. The metal nanopowd...

Highly ordered mesoporous Co3O4 materials have been prepared via a nanocasting route with three-dimensional KIT-6 and two-dimensional SBA-15 ordered mesoporous silicas as templates and Co(NO3)2 · 6H2O as precursor. Through changing the hydrothermal treating temperature of the silica template, ordered mesoporous Co3O4 materials with hierarchical structures have been developed. The larger pores a...

A single suction microelectrode voltage-clamp technique was used to study the actions of lanthanum ions (La3+) on ionic currents in single cells isolated from bullfrog right atrium. La3+, added as LaCl3, blocked the "slow" inward Ca2+ current (ICa) in a dose-dependent fashion; 10(-5) M produced complete inhibition. This effect was best fitted by a dose-response curve that was calculated assumin...