Effects of copper doping on the structural and optical properties of BiFeO3 nanoparticles with antibacterial activity

The primary objective of this study is the synthesis and characterization of Bismuth Ferrite (BiFeO 3 ) and BiFe 1-x Cu x O 3 (Copper-doped BiFeO 3 ) nanoparticles, with Copper ranging from 0.1 to 0.4. X-ray diffraction confirmed the formation of the target nanoparticles along with secondary phases such as Bi 2 O and Fe 2 O 3 . Scanning electron microscopy demonstrated that incorporating Copper doping significantly affected particle morphology, resulting in the development of unique flower-like structures. Structural analysis indicated distortions correlated with rising Copper content, and energy dispersive X-ray (EDX) analysis confirmed the successful integration of Copper, particularly at higher doping levels. However, an excess of Copper induced structural changes that warrant further investigation. Transmission electron microscopy (TEM) revealed that the particles were agglomerated and exhibited irregular shapes, while selected area electron diffraction (SAED) patterns confirmed the perovskite structure of BiFeO 3 . Ultraviolet-visible (UV-Vis) spectroscopy demonstrated that BiFeO 3 has a band gap of 1.5 eV, which decreases to a range of 1.2–1.6 eV with increased Copper doping. Fourier-transform infrared (FTIR) spectroscopy highlighted significant vibrational peaks corresponding to Bi-O, Fe-O, and Cu-O bonds. Antibacterial assays showed notable activity against Gram-positive ( Staphylococcus aureus ) and Gram-negative bacteria ( E. coli and Pseudomonas aeruginosa ), particularly emphasizing efficacy against Pseudomonas aeruginosa . These findings accentuate the effects of Copper doping on the structural, optical, and antibacterial properties of BiFeO 3 nanoparticles, indicating their potential applications in environmental sensing and biomedical fields. • BiFeO 3 and BiFe 1-x Cu x O 3 nanoparticles were synthesized via the sol–gel route. • Samples with x = 0.1–0.4 were successfully prepared and analyzed. • Structural and optical properties were systematically investigated. • Synthesized nanoparticles showed potential antibacterial activity.