Development of NiO-Co₃O₄ nano-ceramic composite materials as novel photocatalysts to degrade organic contaminants present in water

Novel ceramic oxides have been increasingly focused in recent years because of their potential applications in environmental purification especially to treat organic contaminants present in water. In this research work, a set of NiO-Co₃O₄ nano-ceramic composite materials were prepared by a simple reflux condensation method using nickel acetate / cobalt acetate as precursor salts, sodium monododecyl sulphate (SDS) as a surfactant and N,N-Dimethylformamide (DMF) as solvent. The prepared nano-ceramic composites were calcined at different temperatures such as 200, 400, 600 and 800°C for 2 hours each to get the phase pure product. XRD results revealed that all the samples indexed to a cubic crystalline geometry. The presence of metal-oxygen bond (Ni-O and Co-O) was confirmed by FTIR spectroscopy. The presence of Ni, Co and O in the sample was confirmed by EDAX analysis. The existence of particles in nanometer range was shown by SEM. The particle size analysis by light scattering method also confirmed the particles in nanometer range (approximately 270 nm) in all the three samples. The optical behavior of the materials was studied by UV-Vis and PL spectrophotometer. Photocatalytic activity studies carried out with NiO-Co₃O₄ (1.0:1.0) nano-ceramic composites in presence of organic dyes such as, rhodamine B and methyl orange dyes under UV light irradiation (for two hours) resulted in the degradation of 77% and 84% respectively.