Application of surfactants for the synthesis of qualitative hydroxide and metallic cobalt nanopowders
In this work, Co(OH)2 nanopowders (NP) were obtained by chemical precipitation from aqueous solutions of cobalt nitrate Co(NO3)2 and alkali NaOH (10 wt. %) using surfactants - sodium dodecyl sulfate (SDS) and cetylpyridinium chloride (CPC) (0.1 wt. %). Regardless of the preparation conditions, the Co(OH)2 particles have the form of fiakes with an irregular shape and have a size in the nanometer range. It was shown that Co(OH)2 NP obtained with the addition of 0.1 % SDS is the best quality product, since its dispersion increases by more than 2 times as compared to the samples obtained in the presence of 0.1 % CPC and without surfactants. The Co(OH)2 NP synthesized under the condition of adding 0.1 % SDS was chosen to obtain metallic cobalt NP. It was found that for the Co NP sample obtained by hydrogen reduction of Co(OH)2 NP with 0.1 % SDS at 280 °C, the maximum on the histogram of the particle size distribution is in the range 41-50 nm. The obtained Co NP is characterized by a narrow particle size distribution and represents spherical particles sintered with each other.