Effects of Sm-doping on microstructure, magnetic and microwave absorption properties of BiFeO3

Visible Light Photocatalyst and Antibacterial Activity of BFO (Bismuth Ferrite) Nanoparticles from Honey

Visible light-driven photocatalyst BiFeO3 (BFO) nanoparticles were synthesised by the auto-combustion method. The honey was used to fuel the auto combustion method to synthesise the BFO nanoparticles. The structural, optical and morphological activities of the bismuth loaded BFO nanoparticles were characterised by X-ray diffraction (XRD), FTIR, UV, photoluminescence (PL) and SEM analysis, respectively. The bismuth content modifies the lattice parameters of XRD and reduces the bandgap energy. The observed crystallite size varies from 19 to 27 nm and the bandgap region is 2.07 to 2.21 eV. The photo-charge carriers increased upon the BFO nanoparticles and their emission at 587 nm in the visible region of the PL spectrum. The 2% bismuth loaded BFO nanoparticles showed better morphology than 0% and 5% bismuth loaded BFO nanoparticles. The oxidation state of BFO nanoparticles and their binding energies were characterised by X-ray Photoelectron Spectroscopy (XPS) analysis. The methylene blue dye (MB) degradation against 2% BFO nanoparticles showed enhanced catalytic activity (81%) than the remaining samples of BFO nanoparticles. The bacterial activity of BFO nanoparticles was assessed against Gram-positive and Gram-negative bacteria, including S. aureus and E. coli. 2% Excess bismuth BFO nanoparticles exhibit better antibacterial activity. Comparatively, 2% Excess bismuth BFO nanoparticles derived an outstanding crystallinity, charge separation, and reduced bandgap activities. Based on these findings, BFO nanoparticles may be applicable in drug delivery and water remediation applications.

Tunable magneto-optical and interfacial defects of Nd and Cr-doped bismuth ferrite nanoparticles for microwave absorber applications

Tunable microwave absorption characteristics are highly desirable for industrial applications such as antenna, absorber, and biomedical diagnostics. Here, we report BiNd_xCr_xFe_1-2xO₃ (x = 0, 0.05, 0.10, 0.15) nanoparticles (NPs) with electromagnetic matching, which exhibit tunable magneto-optical and feasible microwave absorption characteristics for microwave absorber applications. The experimental results and theoretical calculations demonstrate the original bismuth ferrite (BFO) crystal structure, while Nd and Cr injection in the BFO structure may cause to minimize dielectric losses and enhance magnetization by producing interfacial defects in the spinel structure. Nd and Cr co-doping plays a key role in ordering the BFO crystal structure, resulting in improved microwave absorption characteristics. The BiNd_0.10Cr_0.10Fe_1.8O₃ (BNCF2) sample exhibits a remarkable reflection loss (RL) of -37.7 dB with a 3-mm thickness in the 10.15 GHz-10.30 GHz frequency region. Therefore, Nd and Cr doping in BFO nanoparticles opens a new pathway to construct highly efficient BFO-based materials for tunable frequency, stealth, and microwave absorber applications.