Thermal nanosizing: novel route to synthesize manganese oxide and zinc oxide nanoparticles simultaneously from spent Zn–C battery

Abstract

Spent batteries are one of the fast-growing waste streams in electronic waste due to their low cost, maintenance and versatile applications. In this study, a novel thermal route, using spent waste battery is proposed for synthesis of manganese oxide (MnO) and zinc oxide (ZnO) nanoparticles simultaneously instead of metal separation approaches. Thermal transformation of zinc-carbon (ZnC) battery black mixture at 900 °C under argon atmosphere in horizontal quartz tube furnace facilitated the formation of ZnO nanoparticles, after condensation, leaving behind the MnO nanoparticle in the residue. MnO nanoparticles are known to be high capacity anode materials for lithium ion batteries. ZnO has wide band gap and can be used in sensor and electronics applications. Mechanism of MnO and ZnO nanoparticles formation from spent ZnC battery called “Thermal nanosizing”, is established. Characterization of spent ZnC battery was conducted and synthesized nanoparticles are confirmed by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and energy dispersive spectroscopy techniques. Morphological analysis was conducted by field emission scanning electron microscopy, transmission electron microscopy and selected area electron diffraction analysis. Both MnO and ZnO nanostructures were spherical shape and within 50 nm in size. “Thermal nanosizing” a novel route, proposed in this study could be a path breaking approach to synthesize MnO and ZnO nanoparticles simultaneously from spent battery and could represent an economic value for industries along with environmental benefits.