Phyto-mediated synthesis of pure phase α-Bi2O3 nanostructures using Rubus ellipticus plant extract: photocatalytic activity and antimicrobial efficacy.

Bismuth-based nanoparticles are promising and widely employed in environmental cleanup. Eco-friendly Bi-based nanoparticle synthesis is being explored for nanoscale fabrication. In this study, we report on the green fabrication of alpha bismuth oxide nanoparticles (α-Bi₂O₃ NPs) using an extract from the Himalayan plant Rubus ellipticus. α-Bi₂O₃ nanoparticles were fabricated using methanol extract of the fruits (REF-NPs) and leaves (REL-NPs) of Rubus ellipticus. The optimal synthesis of α-Bi₂O₃ NPs was evaluated through X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FE-SEM), high-resolution transmission electron microscope (HR-TEM), UV-vis spectroscopy, and X-ray photoelectron spectroscopy (XPS) techniques for crystal structure, shape, and optical characteristics. The visible light photocatalytic degradation of toxic dye-Congo red using REF-NPs and REL-NPs was performed. The photocatalytic activity of the synthesized NPs was estimated to be in order of REL-NPs > REF-NPs, with photo-degradation efficiencies of 89.2% and 84.2%, respectively, for Congo red. REL-NPs exhibited the highest rate, which was found to be 1.4 times higher than the REF-NPs sample. Photodegradation experiments revealed that the fabricated α-Bi₂O₃ exhibits enhanced degradation performance for toxic Congo red dye. The antimicrobial efficacy of REL-NPs and REF-NPs against Gram-positive (S. aureus and B. subtilis) and Gram-negative (E. coli, K. pneumoniae, and P. aeruginosa) bacteria, was determined. This work presents a simple green method for producing innovative α-Bi₂O₃ as a remarkable nanomaterial for aquatic bodies to break down dangerous pollutants by visible light photodegradation and as an antibacterial agent. [ABSTRACT FROM AUTHOR]