The growing demand for cobalt, primarily driven by the rapid growth of the rechargeable battery industry, has resulted to a significant increase in cobalt prices. Provided the economic and environmental implications of cobalt shortage, the development of efficient and sustainable methods for the recovery of cobalt from spent batteries has become a critical research priority. This study focuses on the design and synthesis of novel amic acid extractants for the selective recovery of cobalt from other base metal ions, contributing to a more sustainable and circular economy.
A series of the synthesized extractants exhibited high selectivity for Co(II) over Ni(II) and Mn(II) ions. The extraction efficiency was influenced by factors such as ligand structure, concentration, and pH. The recyclability of the extractant was demonstrated, highlighting its potential for sustainable metal recovery. The study discussed valuable insights into the design and optimization of extractants for selective metal ion separation.
The coordination chemistry underlying the solvent extraction of base metal ions using tridentate amic acid extractants was investigated experimentally by slope analysis method. Additionally, to confirm the extraction experimental data and conclude the mode of extraction mechanism X-ray crystallography and DFT calculations were investigated. These techniques offered valuable insights into the structure and properties of the extracted metal-ligand complexes. The 2:1 ligand-to-metal stoichiometry, confirmed by both experimental and computational methods, highlights the importance of ligand design in achieving selective metal ion extraction. The impact of n-alkyl substituents on ligand properties and metal-ligand interactions was investigated through DFT calculations. The strong agreement between experimental and computational results highlights the reliability of DFT as a tool for predicting the behaviour of metal-ligand complexes.