Sustainable Precious Metal Recovery from Electronic Waste: Advances in Green Leaching and Photocatalytic Dissolution

Abstract

Electronic waste (e-waste) is one of the fastest-growing solid waste streams worldwide and contains precious metals alongside polymers and potentially hazardous inorganic constituents. Its rapid accumulation therefore presents both a significant secondary resource value and a growing environmental challenge. Developing efficient, selective, and sustainable strategies for precious metal recovery from e-waste has consequently become a critical scientific priority in materials science and environmental engineering. This review summarizes recent advances in the sustainable recovery of precious metals from e-waste, with particular emphasis on halide-based coordination systems, sulfur-containing ligands, ionic liquids, deep eutectic solvents, and organic ligand-assisted leaching. Strategies for improving precious metal selectivity while minimizing chemical consumption and environmental impacts are critically discussed. Emerging recovery mechanisms, including photocatalytic dissolution (reactive oxygen species, interfacial charge transfer, ligand coordination regulation) and process intensification are also highlighted. Furthermore, the environmental sustainability, energy requirements, and scalability of these technologies are evaluated from life cycle and process engineering perspectives. Finally, key challenges and future research directions are outlined to advance efficient, selective, low-carbon, and environmentally responsible precious metal recycling from e-waste.

Keywords

Precious metal recycling / Electronic waste / Sustainable strategy / Photocatalytic dissolution / Clean technology

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