Structural, optical and photocatalytic properties of zinc oxides obtained from spent alkaline batteries

Abstract

The structural, optical and photocatalytic properties of two zinc oxides prepared from spent alkaline batteries were analysed. After leaching the anode of alkaline batteries, zinc was precipitated from the leachate liquor by introducing oxalic acid (O-ZnO) or sodium carbonate (C-ZnO). The structure of ZnO samples were analysed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), SBET, DRS-UV-Vis spectroscopy and positron annihilation lifetime spectroscopy (PALS). Both oxides present the ZnO wurzite structure and similar morphology. C-ZnO presents a cell lower lattice parameters and bang gap energy (2.99 eV) than O-ZnO (3.05 eV), possibly due to higher concentration of oxygen vacancies. The photocatalytic activity in the degradation of methylene blue (MB) of O-ZnO (achieving 70% MB degradation at 90 min) was superior to C-ZnO, due to its higher surface area and degree of crystallinity and lower bulk/surface defects ratio.

Impacts of the reactants on the synthesis of ZnO particles in glycerol-based solvents

“…Shapecontrolled ZnO particles within acceptable reliability can be obtained by several liquid-based procedures of relatively easy implementation, such as direct precipitation, hydrothermal or solvothermal synthesis, sol-gel, and microwave/ultrasoundassisted synthesis. [13][14][15][16][17] Nevertheless, innovative methods of ZnO synthesis are continuously in development. These methods have explored supraand macromolecular arrangements as templates that can be formed by macromolecules (ex.…”

“…Shape-controlled ZnO particles within acceptable reliability can be obtained by several liquid-based procedures of relatively easy implementation, such as direct precipitation, hydrothermal or solvothermal synthesis, sol–gel, and microwave/ultrasound-assisted synthesis. 13–17…”

Design of Catalysts for Glycolysis of Polyethylene Terephthalate from Spent Batteries

“…[31] These solids were used in different reactions of interest. [32,33] In addition, a previous theoretical study emphasized the role of vacancies on the structural, electronic and magnetic properties of undoped and Mn-doped ZnO using DFT calculations. [34] In this study, two Mn-doped ZnO powders were prepared by mechanical milling, using MnO x and ZnO obtained from the recycling of spent alkaline batteries.…”

“…In a previous work of Gallegos et al ., pure and mixed manganese and zinc oxides have been obtained from spent alkaline and Zn−C batteries by an innovative biohydrometallurgical process [31] . These solids were used in different reactions of interest [32,33] . In addition, a previous theoretical study emphasized the role of vacancies on the structural, electronic and magnetic properties of undoped and Mn‐doped ZnO using DFT calculations [34] …”

Otimização da Rota Sintética Glicerol-Ureia para Produção de Nanopartículas

“…Among these, solvent-based synthesis appears to be the most flexible path to their obtention, once it allows the shape and size control, and many properties of ZnO-NPs are size and shape-dependent [3,15]. Thereby, many liquid-phase methods were reported in the literature, such as hydrothermal or solvothermal preparations, controlled or direct precipitation, sol-gel, emulsion and microemulsion systems, microwave and ultrasound synthesis [16][17][18][19][20][21][22][23][24][25][26][27][28]. Moreover, the use of macromolecules (i.e.…”