Three-dimensional (3D) vertically aligned carbon nanotube (CNT) patterns were utilized as templates for fabricating mesoporous hybrid architectures composed of CNTs and various crystalline metal oxide (MO; M = Co, Zn, Mn) nanoparticles by a microwave-assisted chemical approach. Post-synthesis thermal treatment of the CNT/MO patterns culminated in structural reorganization, depending on the trea...

The construction and use of ‘‘dynamic potential–pHdiagrams’’ (DPPDs), that are intended to extend the usefulness of thermodynamic Pourbaix diagrams to include kinetic considerations is described. As an example, DPPDs are presented for the comparison of electrocatalysts for water oxidation, i.e., the oxygen evolution reaction (OER), an important electrochemical reaction because of its key role i...

The identities of photoexcited states in thin-film Co3O4 and the ultrafast carrier relaxation dynamics of Co3O4 are investigated with oxidation-state-specific pump−probe femtosecond core level spectroscopy. A thin-film sample is excited near the 2.8 eV optical absorption peak, and the resulting spectral changes at the 58.9 eV M2,3edge of cobalt are probed in transient absorption with femtosecon...

X-ray photoelectron and absorption spectroscopies (XPS and XAS) combined with on-line mass spectrometry were applied under working catalytic conditions to investigate the methanol oxidation on cobalt. Two cobalt oxidation states (Co3O4 and CoO) were prepared and investigated as regards their influence on the catalytic activity and selectivity. In addition adsorbed species were monitored in the ...

Sphere-like shaped cobalt oxide nanoparticles (Co3O4) were synthesized by a simple wet chemical method using cobalt chloride as precursor and cetyl trimethylammonium bromide (CTAB) as surfactant. Their structural and surface morphologial properties were characterized by high resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM) and X-ray diffra...

Among all type of batteries, Lithium Air Batteries (LAB) are considered to be the most effective due their highest energy density around 11900 Wh/kg but there some major issues being faced by LAB such as large overpotential, poor cycle life, low current density, and decreased efficiency. The solution these is primarily dependent on proper selection an electrocatalyst. A new approach for using a...

Films of brucite-type cobalt hydroxide with nanorod morphology and hydrotalcite-type cobalt hydroxide with nanosheet morphology films were fabricated by heterogeneous nucleation in a chemical bath using water and a mixed solution of water–methanol as solvents, respectively. Since oxygen is around 25 times more soluble in methanol than in water, a methanol solution was used to convert a part of ...

A Co3O4/Fe2O3 composite nanofiber-based solar photocatalyst has been prepared, and its catalytic performance was evaluated by degrading acridine orange (AO) and brilliant cresyl blue (BCB) beneath solar light. The morphological and physiochemical structure of the synthesized solar photocatalyst was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-...

Due to the greenhouse effect, enormous efforts are done for carbon dioxide reduction. By contrast, more attention should be paid for the methane oxidation and conversion, which can help the effective utilization of methane without emission. However, methane conversion and utilization under ambient conditions remains a challenge. Here, this study designs a Co3O4/ZrO2 nanocomposite for the electr...

In order to explore high efficiency microwave absorption materials, heteronanostructured Co@carbon nanotubes-graphene (Co@CNTs-G) ternary hybrids were designed and produced through catalytic decomposition of acetylene at the designed temperature (400, 450, 500 and 550 °C) over Co3O4/reduced graphene oxide (Co3O4/RGO). By regulating the reaction temperatures, different CNT contents of Co@CNTs-G ...