Biosynthesis of Titanium Dioxide Nanoparticles for Antibacterial and Photocatalytic Activity Using Justicia adhatoda Leaf and Cissus quadrangularis Leaf Extract

The extensive use of antibiotics has led to the emergence of bacterial strains resistant to many drugs, posing threats to food safety and public health. Metal oxide nanoparticles, particularly titanium dioxide (TiO₂), have gained attention as promising antimicrobial agents due to their photocatalytic properties. In this study, TiO₂ was synthesized using Justicia adhatoda and Cissus quadrangularis. XRD analysis revealed a mixed anatase-rutile phase with crystallite sizes of 8.7 nm and 8.5 nm. FESEM confirmed nanorod structures (20–80 nm wide), while EDX showed Ti and O with minimal impurities. UV-Vis spectra showed absorption peaks at 308 nm and 309 nm. The nanoparticles exhibited strong antibacterial effects against Staphylococcus aureus and Escherichia coli, along with photocatalytic activity, reducing methylene blue absorption peaks under UV light within 25 min. These findings highlight TiO₂’s potential for wastewater treatment and antibacterial applications.