Discovering Complex Metal Chalcogenide Nanostructures through Nanoreactor-Mediated Synthesis

Complex metal chalcogenide nanostructures, particularly multimetal, multichalcogen systems, represent a largely unexplored frontier of structural and compositional diversity. Indeed, systematic exploration of this design space is constrained by challenges in precisely controlling the nanostructure composition, morphology, and crystal structure. Here, a generalizable strategy is presented to synthesize and discover metal chalcogenide nanostructures with tunable stoichiometries, crystal structures, sizes, and spatial arrangements by leveraging spatially confined reaction environments within scanning probe lithographically prepared phase-separating nanoreactors. By systematic tuning of the nanoreactor chemistry and processing conditions, a broad spectrum of nanoarchitectures is deliberately accessed, including textured polycrystals, previously unreported heterostructures, and high-entropy metal chalcogenides with six elemental components. Correlative electron microscopy reveals how synthetic conditions dictate nanoparticle structure, composition, and morphology, while 4D-STEM uncovers size- and crystal structure-dependent trends in grain size distributions across nanoparticle libraries. Together, this discovery-driven advance establishes a direct link between synthetic design and structural outcomes, offering a pathway to explore the broader metal chalcogenide material genome at the single particle level.