Photocatalytic activity and magnetic properties of Ba₂FeMoO₆ ferromagnetic double perovskite

Ba₂FeMoO₆ samples were prepared using the sol-gel method without and using Cetyltrimethylammonium bromide (CTAB) to study their photocatalytic properties. The structural and morphological properties of the samples were characterized systematically. The Rietveld refinement described a cubic structure with space group Fm-3m and a single phase with no detectable impurity for either. FESEM images showed that the sample's morphology changed significantly with the addition of the CTAB. The BET analysis of the sample containing CTAB (BFMOC) showed that the special surface area of the pores increased ten times compared to parent sample and its pore size decreased. The UV-Vis spectrum of the BFMOC sample showed two absorption peaks at 223 nm and 705 nm in the ultraviolet and visible regions, respectively. Diffuse reflectance spectroscopy (DRS) spectra of the samples showed direct band gaps (∼2eV) for both. Photocatalytic and absorbent properties were observed in both samples. The photocatalytic properties of the samples revealed that they effectively degraded the dye triphenylmethane MG. By adding CTAB, the Curie temperature of the BFMO sample increased from 304 K to 310 K, while saturation magnetization decreased from ∼1.43 μ_B/f.u to ∼0.89 μ_B/f.u. The low coercive field value indicates that the both samples possess soft magnetic and ferromagnetic properties.