Microwave assisted greener synthesis of nickel nanoparticles using sodium hypophosphite

Nickel nanoparticle (NiNP) was synthesized by reduction of less toxic nickel acetate tetrahydrate (Ni(CH3CO2)(2)center dot 4H(2)O) precursor, using sodium hypophosphite monohydrate (NaPH2O2 center dot H2O) under microwave irradiation. By varying the molar ratio of [Ni+2]/[NaPH2O2]/[NaOH], NiNP of 3.8 to 7.1 nm was obtained. Increasing NaOH concentration resulted in morphological change from isolated spherical particles (7.2 +/- 1.5 nm) to agglomerated nano flowers (72 +/- 14 nm). Phase analysis and interplanar spacing measurements confirmed the particles as fcc-Ni. Quantitative analysis showed the presence of P and O due to HPO2(-) radical in reaction product. Addition of small amounts of polyvinylpyrolidone (PVP) or cetyltrimethylammonium bromide (CTAB) resulted in slight increase in particle size. (C) 2012 Elsevier B.V. All rights reserved.