Bimetallic nanoparticles in sustainable systems: Emerging synthesis strategies and cross‑sectoral applications within a circular economy framework

Despite advancements in nanoscience and the widespread use of metallic nanoparticles, the performance of monometallic nanoparticles has been limited by instability, low catalytic efficiency, and susceptibility to deactivation. To address these challenges, scientists have created bimetallic nanoparticles (BNPs) as versatile catalysts and transformative materials, leveraging their unique synergistic structural and functional properties for diverse applications in sustainable domains. Compared with monometallic nanoparticles, BNPs offer improved catalytic, electronic, magnetic, and optical characteristics, which are exploited in cross-sectoral scientific and industrial applications. The current study reviews the emerging synthesis strategies and multi-sectoral applications of BNPs within the circular economy framework. Unlike other studies, the novelty of the current review lies in hybrid and emerging synthesis routes and the multi-sectoral application of BNPs within the circular economy initiatives. The study gives an overview of the properties and classification of BNPs, traditional, hybrid, and emerging BNPs synthesis routes, and multi-sectoral applications of BNPs and their contributions to the circular economy. The innovative relevance of BNPs underpins its applications in hydrogen production, energy storage and conversion, water and environmental remediation, sensors and biosensors, biomedical imaging and therapy, additive manufacturing and coatings, and photocatalysis and CO₂ reduction. By embedding BNPs into the circular economy structures, these materials act as enablers of resource recovery, waste valorization, and regenerative pathways that minimize environmental burdens while maximizing societal benefit. Future research should focus on alleviating the emerging challenges and integrating digital tools to optimize the production process, real-time monitoring, cost-reduction, scalability, and sustainability.