Aifeng Liu

Facile synthesis of porous cobalt oxide microplates and their lithium ion storage properties

Abstract Porous cobalt oxide (Co3O4) microplates have been successfully synthesised via a facile thermal decomposition from plate-like cobalt oxalate complex precursors. The microstructures and morphologies of the obtained Co3O4 materials are characterised by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and N2 adsorption–desorption techniques. The characterisation results show that the obtained Co3O4 microplates are composed of plate-like polycrystalline nanoparticles with lengths of ∼20 nm and widths of ∼10 nm. In addition, these nanoplates aggregate each other to form the porous network with an average pore size of ∼18·9 nm. The obtained porous Co3O4 microplates exhibit high discharge–charge capacities and good rate performances, suggesting a promising application as anode materials for Li ion batteries.

Preparation of mesoporous nanocrystalline tetragonal zirconia for catalytic methane combustion

Abstract Mesoporous nanocrystalline tetragonal zirconia (ZrO2) materials were synthesised via combining the soft templating method with the solid–liquid method. In brief, mesostructured zirconium hybrids were first prepared via the soft templating method and then ground with solid copper nitrate salts followed by low temperature heat treatment and further high temperature calcination in air. Finally, mesoporous nanocrystalline tetragonal ZrO2 materials were obtained after etching in acid solution. The characterisation results indicate that the obtained mesoporous ZrO2 materials have higher specific surface areas in the range of 100–300 m2 g−1 and pore diameters centred at 4·0–5·0 nm. The pore walls are composed of tetragonal ZrO2 nanocrystalline particles with an average size of 1–15 nm. These mesoporous nanocrystalline tetragonal ZrO2 materials as catalysts demonstrate good catalytic activity toward methane combustion, characterised by lower conversion temperatures (650–700°C) and active energies (75–90 kJ mol−1) than those of the reported ZrO2 materials, meaning their potential applications as catalysts or catalyst supporters in methane combustion.