Green and sonogreen synthesis of zinc oxide nanoparticles for the photocatalytic degradation of methylene blue in water

A green chemical and environmentally benign approach for the synthesis of zinc oxide (ZnO) nanostructure has been explored using aqueous solution of Gum Arabic (GA). Moreover, the added value of applying ultrasound energy to the green synthesis route and its effect on the nanoparticles (NPs) characteristics was considered. The scanning electron and transmission electron images revealed the formation of ZnO nanorods with 3:1 aspect ratio. The crystallite size of the nanostructures derived from X-ray diffraction analysis were 40 and 32 nm for the sample obtained via sonogreen and only green methods, respectively. The band gap energies of the green and sonogreen ZnO were calculated as 3.15 and 3.22 eV, respectively, according to optical analysis data. The photocatalytic performance of samples was tested using dye where a complete decolorization following a pseudo-first-order kinetics was achieved. The current approach exemplifies an entirely green nanomaterials synthesis using a natural product GA and their modifications by applying ultrasound energy. This practice can be expanded to the fabrication of other metal oxide NPs.