Synthesis of ZnO through biomimetization of eggshell membranes using different precursors and its characterization

Abstract In this work, nanostructured ZnO powders were fabricated by simply submerging eggshell membranes (ESMs) in a precursor solution. The biomimetization of the ESMs was studied with 0.25 M aqueous solutions of three different precursors (zinc acetate, zinc nitrate and zinc chloride). The powders obtained by biomimetization were compared with powders obtained by the precipitation method with identical precursor solutions. These powders were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and X-ray diffraction (XRD). The results showed the formation of zincite phase for all samples. The biomimetized samples prepared with zinc acetate and zinc nitrate successfully replicated the ESM morphology with nanometric crystallite sizes. The optical bandgap of biomimetized and precipitated samples presented little variation (~3.25 eV), but the photoluminescence spectrum revealed distinct emission for the biomimetizated samples attributed to crystalline defects.