Synthesis and characterization of ZnO nanoparticles prepared by green routes: controlling morphologies by maintaining pH

Abstract The synthesis of metal oxide semiconductor nanoparticles has attracted much attention in recent past. Nanoparticles are broadly used in solar energy conversion, catalysis, varistors, gas sensors, and non-linear optics, etc. Due to their wide band gap properties, zinc oxide nanoparticles are widely used in numerous applications. Zinc oxide nanoparticles have a wide band gap of approximately 3.3 eV. In this work, we have reported synthesis and characterization of ZnO nanoparticles having rod-like, spherical and flower-like structures. We have used zinc acetate dehydrate [Zn(CH 3 COO) 2 . 2H 2 O] and aqueous extract of Dahlia Pinnata leaves and deionized water. Dahlia Pinnata leaves extract has not been previously used to prepare ZnO NPs. It serves as a reducing and capping agent. We have analyzed the presence of chemicals in the extract using FTIR, Raman and NMR spectroscopy techniques. It is found that the unique morphology of ZnO NPs flower-like structures, enhances it's sensing properties in comparison to the spherical ones. We have used UV–vis-nir spectroscopy, x-ray diffraction (XRD), Fourier Transform Infrared Microscopy(FTIR), and Scanning Electron Microscope (SEM) analysis and have explored the opto-electronic properties of ZnO nanoparticles and have correlated with their structural and morphological properties.