Recycling Zn Casing Waste into a ZnO-Cu-Based Electrocatalyst for Selective CO2 Electroreduction to Ethylene.

The fabrication of a nanostructured electrocatalyst was derived from zinc-carbon (Zn-C) battery waste for the electrochemical reduction of carbon dioxide (CO2RR). The zinc casing was converted into zinc oxide (ZnO) nanorods via hydrothermal oxidation and decorated with Cu2O and CuO nanoparticles (NPs) using drop casting to form a ZnO-CuI,II casing electrocatalyst. Electrochemical CO2RR was conducted via chronoamperometric electrolysis at potentials from -1.70 to 0.00 V. The ZnO-CuI,II casing electrocatalyst exhibited selective formation of ethylene (C2H4) with a Faradaic efficiency (FE) of 5.62% at - 1.30 V vs. Ag/AgCl, along with minor production of CH4, CO, and H2. After regeneration, CH4, CO, and H2 were still detected, but C2H4 was absent due to nanoparticle agglomeration and detachment, as shown by scanning electron microscopy. This work highlights a sustainable route for transforming battery waste into functional electrocatalysts for hydrocarbon production via CO2 electroreduction.