Potential of biosynthesized titanium dioxide nanoparticles towards wastewater treatment and antimicrobial activity.

This study reports a green, sustainable, reliable, and cost-effective method for the biosynthesis of titanium dioxide nanoparticles (TiO 2 NPs) using the leaf and stem extracts of Carissa opaca . The newly synthesized biogenic TiO 2 NPs were confirmed and characterized using various analytical techniques, such as Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HRTEM), dynamic light scattering (DLS), zeta potential, X-ray diffraction (XRD), inductively coupled plasma analysis (ICP), and scanning electron microscopy (SEM). Both the electron microscopy, i.e., SEM and HRTEM confirmed the spherical/hexagonal crystalline structure of TiO 2 NPs with an average particle size range from 72.8 to 84.11 nm. These nanoparticles (NPs) exhibited aggregation and possessed a diverse array of functional groups on their surface. Biosynthesized TiO 2 NPs showed excellent photocatalytic activity against methylene blue (MB) with decolorizing efficiency of 87.8% and 91.95%, whereas in case of methyl violet (MV), the decolorizing efficiency of 82.1% and 71.9% was observed with nanoparticles synthesized using leaf and stem extract, respectively. The newly synthesized NPs have also shown good antibacterial potential against Klebsiella pneumoniae and Staphylococcus aureus . This new biomimetic approach offers an economical and environmentally benign alternative for the removal of hazardous dyes and may find a place for antimicrobial applications.