Annealing Temperature Dependence on Magnetic Properties, Crystalline Structure and Photocatalyst Activity of Coprecipitated Cobalt Ferrite (CoFe2O4) Synthesised from Natural Iron Sand

Cobalt ferrite (CoFe2O4) nanopowder was successfully synthesised by the coprecipitation method. For the entire experiment, natural iron sand from the Bengawan Solo River is used as an iron (Fe) cation source. The effect of the annealing temperature of a coprecipitated CoFe2O4 sample from natural iron sand was investigated. The presence of strong metal oxide bond groups at the tetrahedral and octahedral sites is revealed by fourier transform infrared (FTIR) spectral results, owing to the CoFe2O4 characteristic. Then the X-ray diffraction (XRD) pattern confirmed the formation of a single-phase CoFe2O4 with face centred cubic (FCC) crystal structure closely matched to reference data ICDD221086. The crystalline parameters such as lattice parameter and crystallite size modify with the increase of annealing temperature. The saturation magnetisation (Ms) decreases as the annealing temperature rises. In addition, the coercive fields (Hc) increases as the annealing temperature rises. As a result, the annealing temperature affects the performance of the CoFe2O4 photocatalyst. The photocatalytic performance of the annealing temperature sample at 300°C was found to be the best.