Sustainable Nanoparticle Synthesis of Palladium and Platinum Using Mung Bean (Vigna radiata L.) for Circular Metal Recovery

The increasing demand for precious metals and the rising volume of electronic waste highlight the need for environmentally sustainable recovery techniques. This study explores the green synthesis of palladium (Pd) and platinum (Pt) nanoparticles from spent plating solutions using mung bean (Vigna radiata L.) extract as a natural bioreducing and stabilizing agent. The phytochemical constituents of mung bean polyphenols, amino acids, and flavonoids facilitate the reduction of metal ions and the formation of bio-capped nanoparticles. Characterization via UV–Vis spectroscopy, FTIR, SEM, and zeta potential measurements confirmed nanoparticle formation and morphology. The synthesized nanoparticles exhibited sizes ranging from 70 to 100 nm and demonstrated good stability. This work aligns with Sustainable Development Goal (SDG) 12 by promoting responsible production, consumption, and waste management, and supports the circular economy by recovering valuable metals from waste streams through eco-friendly processes. The results indicate that mung bean extract is a promising candidate for nanoparticle synthesis, with potential applications in environmental and agricultural fields.