Synthesis and Characterization of Cobalt Hydroxide, Cobalt Oxyhydroxide, and Cobalt Oxide Nanodiscs

Abstract

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. Characterization of these cobalt-based nanomaterials was 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 characterized each material. The thermal stability of the materials Co(OH)2 and CoO(OH) was established. This research has developed methodology for the synthesis of cobalt oxide and cobalt oxyhydroxide nanodiscs at low temperatures.

Photochemical versus Thermal Synthesis of Cobalt Oxyhydroxide Nanocrystals

“…14,20 They tend to produce large ca. 500 nm aggregates of clustered 20 nm × 20 nm hexagonal nanocrystals, although certain conditions yield isolated 120 nm × 120 nm hexagonal nanocrystals.…”

“…250 nm amorphous flake-like regions (Table 1, Figure 5). 14 The crystalline domain (grain size) obtained from XRD peak Figure 6). This implies that neither hexaaquacobalt(III) nor hexaaquacobalt(II) is a competent intermediate in forming Co(O)OH.…”

Direct Hydrothermal Synthesis of Size-Controlled Co₃O₄ Nanocubes under Highly Condensed Conditions

“…8) Further, it is reported that nano ower-shaped Co 3 O 4 particles show highly reversible lithium storage capability by Chen et al The nano ower was synthesized by way of thermal treatment of the ower-shaped precursor obtained by a solvothermal method. 21) Co 3 O 4 nanocubes, [29][30][31] nanosheets, [32][33][34] nanorings, 35) nanowires, 8,36) nanospheres, 37) and nanoparticles [38][39][40] 43) However, all the approaches have been carried out at low concentrations so that to prevent the aggregation between the particles among the growth process (0.001 0.1 mol/L). For the practical usage of Co 3 O 4 -based nanomaterials, development of a liquid-phase direct synthetic process of Co 3 O 4 nanoparticles under a highly concentrated condition to obtain the desired particles in large quantity.…”

A avaliação mecanística teórica da utilização de oxihidróxido de cobalto (III) em sensores eletroquímicos de tramadol

“…Um dos materiais modificadores, que pode ser capaz de auxiliar a eletrooxidação de tramadol é o oxihidróxido de cobalto trivalente CoO(OH), um semicondutor do tipo p, visto por alguns pesquisadores [36][37][38][39][40] como alternativa ao dióxido de titânio nos sistemas de foto e fotoeletrocatálise. O estudo das suas propriedades eletroanalíticas começou recentemente [41,42], mas já foi mostrado, experimental e teoricamente [43][44][45][46], que o CoO(OH) pode ser ótimo mediador de oxidação de compostos orgânicos em meios neutro e levemente alcalino.…”