A Biodegradable Metal–Organic Framework/Oligomer Composite for Sustainable Gold Recovery and Circular Water Management

Abstract

The rapid growth of artificial intelligence and digital technologies is generating unprecedented e-waste streams rich in secondary gold resources, yet sustainable recovery strategies remain scarce. Here, we report a bioderived, environmentally degradable metal–organic framework (MOF)/oligomer composite (SU-102/pGSH) constructed via host–guest self-assembly of glutathione (GSH) within a Zr-ellagate framework. The composite integrates abundant electron-rich functional groups into a robust porous architecture, achieving a remarkable gold uptake capacity of 4385 mg·g–1, the highest reported for MOF-based adsorbents. It also exhibits outstanding selectivity in complex e-waste leachates. Mechanistic investigations reveal synergistic coordination with abundant electron-rich groups, followed by electron-transfer reduction of Au(III) to Au(0). Importantly, the spent adsorbent could degrade into benign mineral phases and natural metabolites with negligible phytotoxicity, ensuring a safe end-of-life pathway. Preliminary techno-economic analysis indicates favorable economic potential for practical implementation. By integrating efficient gold recovery with sustainable material design and end-of-life management, this work provides a viable strategy for circular water treatment.