Nanoscale design of 1D metal oxides derived from mixed Ni-MH battery/ transition metal dust

Controllable recycling of End-of-life rechargeable nickel-metal hydride (Ni-MH) batteries and by-products of steelmaking to added-value functional nanostructures is desired but challenging. The present work introduces an innovative and high-yield microrecycling strategy to simultaneous synthesis of TM alloy (i.e., Ni-based superalloy) and RE oxide (REO) nanostructures from obsolete Ni-MH batteries mixed with zinc-rich electric arc furnace dust (EAFD). This strategy involves integration of high-temperature thermal isolation followed by thermal nanowiring techniques. The impure thermally-isolated REOs were purified and transformed into one dimensional (1D) nanorods of hybrid REOs. Besides, during high-temperature thermal isolation, defect-rich ZnO with tailored structures of nanorods and nanoribbons were fabricated using controllable vapour deposition. The electrochemical performance of ZnO nanoribbons for oxygen evolution reaction (OER) revealed a considerable overpotential reduction of 131 mV (18%) compared to pure commercial nano-ZnO. This approach is transformational in providing a scalable and cost-effective pathway to facilitate recycling of the challenging, yet critical, waste materials into functional nanostructures for energy and environmental applications.

Automated summary

This study introduces an innovative microrecycling strategy to synthesize TM alloy and RE oxide nanostructures from end-of-life Ni-MH batteries and steelmaking by-products, providing a scalable and cost-effective pathway for recycling waste materials into functional nanostructures for energy and environmental applications. The fabricated ZnO nanoribbons showed a considerable reduction in overpotential for the oxygen evolution reaction compared to pure commercial nano-ZnO.