Biosynthesis of TiO2 nanoparticles using Justicia gendarussa leaves for photocatalytic and toxicity studies

Eco-friendly biosynthesis of polycrystalline titanium dioxide (TiO₂) nanoparticles (NPs) was synthesised using Justicia gendarussa (J. gendarussa) leaf extract as oxidizing agents. They were compared with TiO₂ NPs synthesized using the glacial acetic acid and also studied was the combined effect of synthesis of TiO₂ NPs. The crystalline nature and structural formation of TiO₂ NPs synthesized by different methods were confirmed by the X-ray diffraction technique, and functional groups of materials were confirmed by FT-IR spectroscopy. The synthesized materials were investigated for photocatalytic activity for methylene blue under UV irradiation and toxicity activity against MCF-7 and MDA-MB-231 cells. The result indicates that TiO₂ NPs synthesised by J. gendarussa showed superior and enhanced activity against MCF-7 and MDA-MB-231. Biosynthesized TiO₂ NPs showed higher photodegradation of dyes when compared with other TiO₂ NPs synthesized by different methods. This is due to the alterations in band gap; structural changes and surface area in nanoparticles that increased the activity. Also, nanosphere/disc like morphology of TiO₂ NPs is confirmed using TEM.