Recovering of Silver from End-of-life Silicon Solar Panels Through a Peroxymonosulfate-based Advanced Oxidation Approach

Abstract

Silicon solar panels are critical enablers of the carbon-neutral transition. Silver (Ag), a core material in these panels, faces growing scarcity concerns due to surging production and mounting end-of-life (EoL) volumes. We report a peroxymonosulfate (PMS)-based advanced oxidation process (AOP) for rapid Ag recovery from EoL crystalline silicon (c-Si) solar cells. Our findings show that the high-valent iron species (Fe(IV)) play a pivotal role in catalyzing PMS to generate singlet oxygen and enhance sulfate radical production via the Fe(II)/Fe(IV) redox cycle. Singlet oxygen and sulfate radicals serve as the primary active species for silver oxidation extraction in the PMS/Fe²⁺ system, enabling complete (100%) Ag dissolution within 20 min from diverse types of c-Si cells. An integrated leaching and electrodeposition process recovers high-purity silver (>99%) without employing strong acids, cyanide, or volatile organic solvents. The energy consumption and chemical inputs were just 5% and 2% of those reported in previous literature. This efficient and sustainable approach establishes AOP technology as a viable solution for resource recycling from EoL c-Si cells.