Ultrasound-assisted green biosynthesis of ZnO nanoparticles and their photocatalytic application

Employing plant extracts to obtain nanomaterials is an ecofriendly and highly appreciated synthetic approach. In this work a simple, green chemistry method, based on sol–gel, was used for ZnO nanoparticles synthesis by using two Sudanese medicinal plant extracts: Adanosia digitata (ZnO-A) and Balanites aegyptiaca (ZnO-B) under ultrasonic energy. The X-ray diffraction (XRD) revealed the formation of wurtzite hexagonal ZnO nanostructures, while the scanning electron microscopy (SEM) analysis displayed their diverse morphologies. The X-ray photoelectron spectroscopy (XPS) data showed the impact of extract via the variation in of the O1s and Zn2p3/2 and Zn2p1/2 orbitals binding energy of Zn–O. The UV-visible investigation indicated a variation of bandgap energy (E g ), where the ZnO nanoparticles displayed the lowest E g . The synthesized nanomaterials have exhibited high photocatalytic efficiency towards the methylene blue (MB) dye. The findings revealed the possibility of obtaining nanoparticles with tailored properties by using plants extracts.