**7. Biosynthesis of titanium dioxide (TiO2) nanoparticles**

The high prevalence of TiO2 NPs is due to their many versatile applications resulting from the stability of chemical structure, optical, electrical, and physical properties. These characteristics offer a wide range of TiO2 is present in three different mineral forms such as anatase, rutile, and brocite. It is generally preferred due to its photocatalytic activity [9]. The synthesis of TiO2 NPs by plant leaf extracts is mixed with metal precursor solutions in various reactions and temperature conditions [65]. The high production and widespread use of TiO2 NPs have led to little effort for biogenic production. Several plant species have been investigated for the production of TiO2 NPs. Several processes have been developed in the last two decades to synthesize biogenic NPs. These methods effectively control the properties of NPs in which most of the potential toxicity materials are used (**Table 1**) [66].
