Sustainable recovery of metals from e-waste using deep eutectic solvents: Advances, challenges, and perspectives

The increasing emission of electronic waste (e-waste) accelerates the depletion of natural metal resources and raises growing concerns for human health and environmental sustainability. Herein, the valuable metal recovery driven by the development of a circular economy has increasingly become a focal point in research. Recovering metals from e-waste can rationally allocate resources and significantly alleviate environmental issues; however, it remains challenging. Deep eutectic solvents (DESs) provide an ideal alternative for these separation and recovery processes due to their green properties. This article reviews recent advances in the recovery of metals from e-waste using DESs, encompassing spent battery materials, printed circuit boards, lamp phosphor waste, and end-of-life permanent magnets. Recovery approaches involving redox/coordination leaching, solvent extraction, precipitation, and electrodeposition are discussed within the framework of DESs' unique solvent characteristics, eco-design principles, and technology features. Finally, challenges facing this emerging recovery technology are outlined while future prospects are also envisioned.