Recent advances in the recycling of precious metals using sustainable chemistry

Abstract

Precious metals (PMs) such as silver, gold, palladium, platinum, and rhodium are used not just in traditional industries like jewelry, but also in modern electronics, medicine, catalysis and others. Their scarcity, as well as the environmental impact of current extraction procedures that frequently include harmful compounds such as cyanide and mercury, provide substantial global issues. With a growing interest in sustainable chemistry, researchers are developing eco-benign ways to extract PMs from secondary sources, like electronic waste, spent catalysts which frequently have greater PM concentrations. This review presents a contemporary analysis of PM recovery with focus on underexplored and emergent avenues, such as bio-based leaching, mechanochemistry, photocatalysis, ionic liquids and deep eutectic solvents, and computationally driven ligand design, in addition to reviewing conventional procedures. Sustainability criteria including toxicity, energy use, recyclability, and life-cycle assessment (LCA) are prioritized. Comparative tables and cross-cutting studies reveal which techniques are industrially scalable, which are still in proof-of-concept stage, and where knowledge gaps persist. This review gives a unique perspective on chemical innovation and sustainability evaluation, complementing existing surveys and providing actionable information for academics and industries seeking greener PM recovery.