Synthesis and microstructural properties of zinc oxide nanoparticles prepared by selective leaching of zinc from spent alkaline batteries using ammoniacal ammonium carbonate

• DOI: 10.1016/j.jclepro.2017.02.031
• Publication Date: 2017-02-08T07:30:13Z
• Authors: Félix A. López; Teresa Cebriano; Irene García-Díaz; Paloma Fernández; Olga Rodríguez; Ana López Fernández
• Keywords: Thermogravimetric analysis; Ammonium carbonate

Two different precursors of zinc oxide were prepared via the ammoniacal ammonium carbonate leaching of the black mass obtained during the recycling of alkaline batteries. For a concentration of 0.1 mol/L of ammonium in the leaching solution, zinc basic carbonate, was obtained, while for higher ammonium concentrations (0.5 and 1 mol/L), zinc ammonium carbonate was the final product. These precursors were characterised by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FFIR), Thermogravimetric analysis (TGA/DTG) and Scanning electron microscopy (SEM), and calcined to obtain ZnO. Raman spectroscopy, X-ray diffraction and Transmission electron microscopy (TEM) analysis of the resulting zinc oxide samples indicated a wurtzite hexagonal lattice with a parameter values ranging from 3.23 angstrom to 3.30 angstrom, and c parameter values from 5.18 angstrom to 5.21 angstrom (values close to typical). The room temperature photoluminescence spectra of the zinc oxide samples showed two main bands: a high energy UV-blue band centred at either 412 or 382 nm (depending on the NH3 concentration of the leaching solution used), and a green band centred at 527 nm. These emission bands are comparable to those reported for pure zinc oxide.