Nanostructured bismuth ferrite nanoparticles: synthesis, characterization, electrical/magnetic properties and photocatalytic performance

Abstract

Nanostructured bismuth ferrite (BiFeO₃) single-phase nanoparticles with 76.2% crystallinity and 100% perovskite structure were synthesized using a co-precipitation method. The X-ray diffraction pattern confirmed the perovskite structure of BFO, and Rietveld refinement demonstrated the presence of a triclinic structure with the P1 space group. The Scherrer and Williamson–Hall equations were used to calculate the crystallite size (63 and 83 nm, respectively) with a grain size of almost 246 nm and an activation energy of 0.53 eV. The accumulation of free charges at interfaces, which correlate with the sample bulk and the interface between the compound and electrode space-charge polarization, was the reason behind the high values of ε′. As the frequency increased up to 1000 Hz, both dielectric constant ε′ and dielectric loss ε′ fell quickly. In contrast, at high frequencies, the ε′ became more frequency-independent, notably when ε′ increased with a temperature of up to 423 K. The sample exhibited considerable soft ferromagnetic-like activity due to the acquired nanoscale structure that promotes spin coating in the BiFeO₃ antiferromagnetic phase. The significant coercivity 2624.5 Oe provides each materials in permanent magnetic and transformers. Photocatalytic activity of the BiFeO₃ nanocomposite under UVA-light irradiation was performed using Congo red dye. The maximum photocatalytic degradation efficiency after 200 min for CR was 66%. The exceptional electrical and magnetic characteristics of nanostructured BiFeO₃ provide new possibilities for its use in potential technological applications, i.e., spintronics, data storage microelectronics, and water treatment.