Microwave approach and thermal decomposition: A sustainable way to produce ZnO nanoparticles with different chemo-physical properties

Two different synthetic approaches such as thermal decomposition method and microwave-assisted procedure were compared for the synthesis of nanosized ZnO. The two procedures were tested using zinc acetate as precursor as is, or in the presence of two coadjutants, one of anthropic origin (melamine) and one derived from the reuse of agricultural waste (wine extracts). All the samples were physico-chemically characterized in order to evaluate the influence of the synthesis conditions on the properties of the materials that were characterized by N2 adsorption/desorption at 77 K and Field Emission-Scanning Electron microscopy measurements for evaluating the morphology, X-ray diffraction for examining the crystalline structure and X-Ray photoelectron spectroscopy for evidencing the surface composition of the nanoparticles. In order to verify the influence of the synthesis procedure on the electrical and optical properties of the ZnO nanoparticles, forecasting their use in photocatalytic applications, also the band gap of materials was evaluated by means of UV–Vis spectroscopy and Tauc plot. A final comparison of all the results allowed to evidence advantages and disadvantages of the procedures under study pointing out the importance of deepen the study of microwave-based synthetic approaches.