A novel ZnO-MgO-Gd₂O₃ nanocomposite synthesized with Ocimum basilicum seed extract for enhanced photocatalysis

Recent years have seen ternary metal oxide nanocomposites attract widespread research interest due to their remarkable photocatalytic properties and applications. This study introduces a novel ternary ZnO-MgO-Gd₂O₃ nanocomposite through a green synthesis protocol with Ocimum basilicum L. seed extract that avoids harmful chemicals. A comprehensive set of analytical techniques was employed to accurately describe the structural, morphological, and optical properties. XRD analysis provided insights into the crystal structure, as an increase in crystal size from 12.06 nm at 500 °C to 12.34 nm at 600 °C was calculated. FE-SEM with EDS spectroscopy showed the formation of spherical nanoparticles with uniform distribution and the elements in the nanocomposite. DRS spectroscopy confirmed an increase in the band gap with increasing temperature from 3.7 eV (500 °C) to 2.9 eV (600 °C), while FTIR provided information on the functional groups. Also, the photocatalytic performance of the nanocomposite was evaluated and showed significant ability to degrade organic dyes under specific conditions (nanocomposite concentration = 26 mg, UVA lamp power = 20 W, and λ = 365 nm). It is worth noting that the nanocomposite has a degradation rate of 99.5% for EBT (pH = 10 after 105 min), 98.5% for MB (pH = 10 after 75 min), 91.5% for MO (pH = 10 after 105 min), and 72% for RhB (pH = 2 after 105 min). These results indicate the potential of the nanocomposite as a strong photocatalyst for wastewater treatment applications.