Preparation of stable porous nickel and cobalt oxides using simple inorganic precursor, instead of alkoxides, by a sonochemical technique

Porous nickel and cobalt oxides were prepared using NiSO4 · 6H2O and anhydrous Co(CH3COO)2, a precursor other than alkoxides and cetyltrimethylammonium bromide as organic surfactant. The sonication method has been used for such synthesis. The surfactants were removed by calcination, as well as by solvent extraction and it is extent was examined by IR spectroscopy. The trend of removal of surfactant was followed by TGA studies and the change in phases by DSC. The products were identified by XRD. Peak in low angle XRD indicates the porous nature of the oxides. The morphology of the pores was studied by transmission electron microscopy. The pores were found less ordered, having an average size of 4–6 nm. The Brunauer–Emmet–Teller surface areas of the as-prepared, as well as the treated samples are reported having H2 and H4 type hysteresis for Ni and Co, respectively.