Structural properties of ZnO obtained from spent batteries through the Pechini method

M.V. GALLEGOS; M. MEYER; J. SAMBETH; L.C. DAMONTE

Helsinski

Conferencia; 19th International Conference on Positron Annihilation; 2022

University of Helsinski

Zinc oxide is an interesting material with useful applications, such as catalysis, electronics, solar cells, sensors, acoustics, etc. The versatility of this material is related to its structural and textural properties, which depend on the synthesis methods used. In the Pechini method, a polyhydroxy alcohol (ethylene glycol) and a hydroxycarboxylic acid (citric acid) are used.These form a polymer network in which the metal ions are evenly distributed. During the calcination stage, the polymer network collapses, and the metal oxide powder remains. The powders are extremely pure and very homogeneous compared to powders prepared by conventional methods.Zn is part of alkaline batteries, so the technological possibility of recovering Zn as ZnO provides an environmental solution. In this work, we intend to recover Zn2+ ions from exhausted batteries using different acids. Starting from zinc nitrate or zinc chloride solutions, it is intended to synthesize ZnO through the Pechini method.The obtained solids were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflectance spectroscopy. The peculiar morphologies observed could be related to the different counterions in the starting solutions. Positron annihilation lifetime spectroscopy (PALS) was applied to verify the ability of positrons to sense the effect of initial solutions on the morphological and structural properties.