Photocatalytic and photovoltaic applications of green synthesized titanium oxide (TiO2) nanoparticles by Calotropis gigantea extract

Titanium di oxide (TiO2) nanoparticles were prepared by green synthesis method using leaves, seeds, and flower solvent extract of Calotropis gigantean medicinal plant. The X-ray diffraction (XRD) analysis of the prepared TiO2 nanoparticles shows tetragonal structure of anatase phase TiO2. The quantum confinement of the TiO2 particles by the inclusion of active biomolecules was confirmed by optical studies. The poly-crystalline nature of the prepared nanoparticles was confirmed by XRD and SAED analysis. The particle size reduction and increase of band gap energy are noted with Calotropis gigantean leaf assisted TiO2, while it increases with flower and seed assisted TiO2. The prepared nanoparticles exhibit the size dependent photocatalytic activity and solar cell fabrication. Calotropis gigantean leaf assisted TiO2 NPs had the highest photocatalytic activity, completely degrading methylene blue in 60 min with an 96 % of degradation, due to a low recombination rate of photo-generated electrons and holes. The prepared Calotropis gigantean plant assisted TiO2 nanoparticles boosted the concentration of OH & BULL; and O2 & BULL; radicals in the solution, which is beneficial for enhancing the photodegradation rate of organic compounds. Plant derivative based TiO2 nanoparticles are the best candidates due to simplicity and cost-effectiveness leading to economical and operational advantages in the large-scale synthesis of nanoparticles. & COPY; 2023 Elsevier B.V. All rights reserved.