Facile green synthesis and characterization of zinc oxide nanoparticles using tragacanth gel: investigation of their photocatalytic performance for dye degradation under visible light irradiation

In this work, zinc oxide nanoparticles have been synthesized via the green and easy sol-gel method. Then, they have been characterized by Fourier transforms infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), UVVisible Diffuse Reflectance spectroscopy (DRS), transmission electron microscope (TEM), field emission scanning electron microscopy (FESEM), and Brunauer Emmett Teller (BET) analysis. The XRD result showed that ZnO nanoparticles have a hexagonal phase structure with an average crystallite size of 18 nm. The TEM results revealed the nanoparticles size of about 25-35 nm with spherical morphology. The Tauc theory was used to calculate the optical band gap which was found to be 3.03 eV. BET analysis displayed that the specific surface area of the ZnO NPs was 15.87 m²/g. The impact of various parameters such as catalyst dosage, dye concentration, visible light irradiation and time were evaluated in dye degradation. The ZnO NPs shown high photocatalytic performance for degradation of malachite green dye at room temperature in aqueous solution so that 92% of malachite green (MG) was degraded in 90 min.