Core-Shell Nanocatalysts of Co3O4 and NiO Shells from New (Discarded) Resources: Sustainable Recovery of Cobalt and Nickel from Spent Lithium-Ion Batteries, Ni-Cd Batteries, and LCD Panel

This work focuses on end-of-life Ni-Cd and Li-ion batteries and introduces a novel approach to prepare two types of core-shell nanocatalysts consisting of NiO and Co3O4 as the shells, respectively. Using a hydrometallurgical technique, we are able to successfully recover metals such as Co and Ni, and then use the recovered metals as precursors in preparation of catalysts via a precipitation technique using an alumina-borosilicate substrate which has been fabricated from scrap LCDs. The structures of the obtained nanocatalysts are carefully investigated by electron microscopes. It is revealed that the NiO show nanowire structure, while the Co3O4 has nanobelt structure shells over the core of the substrates. The synthesized nanomaterials are used as photocatalysts to decompose methylene blue as an organic pollution model available in wastewater. Our nanocatalysts exhibit high photocatalytic performance with four times the reusability under a very low power UV (9 W) irradiation.