Synthesis and characterization of cobalt hydroxide, cobalt oxyhydroxide, and cobalt oxide nanodiscs

Cobalt hydroxide, cobalt oxyhydroxide and cobalt oxide nanomaterials were synthesized through simple soft chemistry. The cobalt hydroxide displays hexagonal morphology with clear edges 20 nm long. This morphology and nanosize is retained through to cobalt oxide Co3O4 through a topotactical relationship. Cobalt oxyhydroxide and cobalt oxide nanomaterials were synthesized through oxidation and low temperature calcination from the as-prepared cobalt hydroxide. Characterisation of these cobalt-based nanomaterials were fully developed, including X-ray diffraction, transmission electron microscopy combined with selected area electron diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and thermal gravimetric analysis. Bonding of the divalent cobalt hydroxide from the oxyhydroxide and oxides by studying their high resolution XPS spectra for Co 2p3/2 and O 1s. Raman spectroscopy of the as-prepared Co(OH)2, CoO(OH) and Co3O4 nanomaterials characterised each material. The thermal stability of the materials Co(OH)2 and CoO(OH) were established. This research has developed methodology for the synthesis of cobalt oxide and cobalt oxyhydroxide nanodiscs at low temperatures

Gallium-Doped Boehmite Nanotubes And Nanoribbons. A TEM, EDX, XRD, BET, And TG Study

Gallium doped boehmite nanostructures with varying gallium content have been prepared at low temperatures via a soft-chemistry route in the presence of poly (ethylene oxide) (PEO) surfactant. The effect of gallium content, hydrothermal temperature and mixing procedures on the growth of boehmite nanostructures was systematically studied. The resultant boehmite nanostructures were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) microanalysis, X-ray diffraction (XRD), N2 adsorption and thermogravimetric analysis (TGA). Nanotubes with average length of ~90 nm, internal and external diameters of 2~5 nm and 3~7 nm respectively were formed when added gallium molar percentage ≤5 %; when added gallium percentage>10%, an amorphous phase dominated the sample with a mixture of nanosheets, nanotubes and nanoribbons was also formed. Synthesis at slightly higher temperatures (120 °C) for added gallium molar percentage ≤5 % resulted in longer nanotubes. For high gallium content boehmites large crystals are formed when hydrothermally treated at 120 °C. The detailed characterization of the resultant gallium doped boehmite nanostructures is presented