Photocatalytic Synthesis of Quinazolinone Derivatives as Mediated by Titanium Dioxide (TiO₂) Nanoparticles Greenly Synthesised via Citrus limon Juice

In this study, we focused on the ultrasonic synthesis of titanium dioxide (TiO₂) nanoparticles via a green chemistry process using Citrus limon (lemon) juice. XRD diffractograms and Raman spectroscopy revealed the anatase structure of TiO₂, SEM analysis showed nanometric particle sizes, and FTIR spectroscopy confirmed the presence of the synthesized nanoparticles. The catalytic performance of the biosynthesised nanoparticles was evaluated for the synthesis of sulphur-substituted quinazolinone derivatives under UV irradiation. The final products were achieved in 6–8 h with good yields (79–91%).