Comparative studies of cobalt and nickel oxides synthesised using steady-state γ-radiolysis

The preparation of nano metal oxides of cobalt and nickel has been carried out by steady–state γ–radiolysis technique with aniline as a stabiliser and various alcohols as solvents. The UV–visible spectroscopy shows the progress of the reactions with sharp peaks observed in the range of 430–500 nm in cobalt solutions and nickel exhibiting peak in the range between 330 and 400 nm indicating the formation of Co3O4 and NiO respectively. X–ray diffractograms exhibit peaks that match with standards corresponding to the patterns of Co3O4 and Ni2O3 as the major phase. TEM shows the formation of fibres for cobalt oxide and beautiful spheres in case of nickel oxide. The fringe widths found out from HRTEM were seen to be ∼0.25 and 0.23 nm confirming the presence of respective oxides. The XPS studies depict the oxidation states with major peaks seen at ∼781.6 and 855.8 eV establishing the formation of Co3O4 and Ni2O3 respectively.