Simultaneous thermal preparation of ultra-pure ZnO nano-wires and recovery of pure MnO from waste alkaline batteries

Abstract

A simultaneous preparation of 100 % pure zinc oxide nano-wires and recovery of pure manganese oxide catalysts from waste alkaline batteries was studied by a laboratory scale thermal processing technique with temperature variation (850-950 degrees C) at various residence times (1-3 h) under a constant Ar atmosphere and 1 atm pressure. The change in structure and morphology of the products obtained at different experimental parameters were analysed through SEM and TEM analysis. The zinc oxide nano-wires obtained at 950 degrees C, 1 h showed consistency in structure and morphology and also purity as confirmed by XRD, XPS, and EDS results. The obtained zinc oxide nano-wires at 850-950 degrees C showed a variance in the average diameter from similar to 82 to similar to 127 nm as observed under TEM with an observed morphological change with increase in temperature/time. Photoluminescence spectra was obtained for ZnO nano-wires which showed two emission bands in UV range and visible range respectively. This thermal investigation process exhibits a roadway to recycle waste alkaline batteries by recovering MnO and ZnO while reducing the burden on landfills and environment alike.