Monodispersed nickel(II) particles were achieved by ageing aqueous solutions of NiSO4·6H2O in the presence of urea, at 90°C for 3.5 h. Working up this colloidal dispersion led to a green powder with the stoichiometry 5[Ni3(OH)5(NCO)]·[NiCO3]·[H2O]. This mixed salt was characterised by extensive spectroscopic investigations and chemical–physical analyses. The nickel intermediate was further thermally decomposed at various temperatures, under both aerobic and anaerobic conditions, and gave black mono dispersed particles of Ni(II) and Ni(III) oxides. The phase transformations were studied in detail and the oxidation products (NiO and NiO(OH)) were characterised.
Synthesis and full characterisation of nickel(II) colloidal particles and their transformation into NiO / F. Porta, S. Recchia, C.L. Bianchi, F. Confalonieri, G. Scari. - In: COLLOIDS AND SURFACES. A, PHYSICOCHEMICAL AND ENGINEERING ASPECTS. - ISSN 0927-7757. - 155:2-3(1999), pp. 395-404.
Synthesis and full characterisation of nickel(II) colloidal particles and their transformation into NiO
F. Porta;C.L. Bianchi;G. Scari
1999
Abstract
Monodispersed nickel(II) particles were achieved by ageing aqueous solutions of NiSO4·6H2O in the presence of urea, at 90°C for 3.5 h. Working up this colloidal dispersion led to a green powder with the stoichiometry 5[Ni3(OH)5(NCO)]·[NiCO3]·[H2O]. This mixed salt was characterised by extensive spectroscopic investigations and chemical–physical analyses. The nickel intermediate was further thermally decomposed at various temperatures, under both aerobic and anaerobic conditions, and gave black mono dispersed particles of Ni(II) and Ni(III) oxides. The phase transformations were studied in detail and the oxidation products (NiO and NiO(OH)) were characterised.Pubblicazioni consigliate
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