Structural, magnetic and photocatalytic properties of La and alkaline co-doped BiFeO₃ nanoparticles

Abstract BiFeO₃ is synthesized by the solvothermal method and the effect of La and co-doped alkaline elements (Ba and Ca) on the structural, magnetic and photocatalytic properties of BiFeO₃ are studied. XRD pattern confirms the rhombohedral structure of BiFeO₃ and Rietveld refinement is performed to study the change in bond length and angles of the samples. The structural distortion induced by dopants is further analyzed by Raman spectra. Particles of irregular morphology are observed from TEM. The optical band gap of the samples is found to be increased on doping and is in the visible region (2.02-2.11 eV). Magnetic measurements reveal that there is an enhancement of saturation magnetization in doped samples. The degradation of methylene blue is carried out in the absence and presence of H₂O₂ at two different pH values 2 and 6 under visible light. In the presence of H₂O₂ at pH value 2, the degradation of dye is found to be higher for BFO and the decrease in the photocatalytic activity rate is observed in the case of doped samples.