Antimicrobial and antioxidant potential of eco-friendly synthesized Sb–Bi ₂ O ₃  nanocomposites using cinnamomum verum bark extract

The increasing demand for environmentally sustainable nanomaterial synthesis has led to the development of green approaches using plant extracts. In the present study, Cinnamomum verum bark extract was used as a reducing and stabilizing agent for the eco-friendly synthesis of Sb–Bi2O3 nanocomposites. The phytochemicals present in the extract, including flavonoids, polyphenols, tannins, and cinnamaldehyde, facilitate the reduction of metal ions and stabilize the formed nanoparticles. The synthesized nanocomposites were characterized using sophisticated instrumentation techniques, Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–Vis) spectroscopy, along with scanning electron microscopy (SEM‑EDS), which revealed the heterogeneous nature of nanoparticles with sizes ranging from approximately 20–200 nm and confirmed the crystalline nature of the nanocomposites. The synthesized nanomaterials were evaluated against Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa, and exhibited significant antibacterial activity, with the highest inhibition zone of 21 mm against K. pneumoniae. The antioxidant potential of the newly synthesized nanocomposites was screened using the DPPH radical scavenging assay, which showed enhanced activity compared with Bi2O3 nanoparticles. These findings suggest that green-synthesized Sb–Bi2O3 nanocomposites may have promising perspectives in biomedical and pharmaceutical fields.