Ionic liquids as multifunctional media for sustainable synthesis of silver nanoparticles: Mechanisms, advances and future directions

Silver nanoparticles (AgNPs) have become fundamental components of modern nanotechnology owing to their exceptional antimicrobial, catalytic, and optical properties. Nevertheless, current synthesis strategies are constrained by an inherent trade-off: conventional chemical approaches offer high precision but rely on many molecular organic compounds and hazardous chemicals for each synthesis, while biogenic synthesis often suffers from poor reproducibility and the formation of complex biomolecular coronas that hinder precise morphological control. In this context, ionic liquid (IL)-mediated synthesis has emerged as a promising alternative that bridges the gap between environmental sustainability and structural precision. Drawing on two decades of research (2005–2025), this review elucidates how ILs have transformed AgNPs fabrication by functioning not merely as solvents, but as tunable reaction environments that govern nanoparticle formation, stabilization, and surface functionality. The convergence of IL chemistry with energy-efficient synthesis technologies and biogenic approaches is creating new opportunities to enhance nanoparticle performance, process efficiency, and sustainability. Despite these advances, challenges related to toxicity, cost, and large-scale implementation continue to impede industrial translation. Addressing these barriers will require deeper mechanistic understanding, improved economic feasibility, and predictive design strategies. By integrating mechanistic insights with technological advancements, this review provides a strategic framework for advancing IL-mediated AgNPs synthesis from laboratory research to commercially viable applications across biomedical, sensing, environmental and industrial sectors.