Combinatorial cation exchange for the discovery and rational synthesis of heterostructured nanorods

Precisely engineering heterostructured nanoparticles that incorporate different materials in specific configurations requires appropriate design guidelines and synthetic tools. Cation exchange reactions offer a capable pathway for rationally transforming simple nanoparticles into a large library of complex heterostructured products, but existing capabilities remain limited, leaving many compositions and architectures out of reach. Here, we establish a combinatorial solution chemistry platform to accelerate the discovery and rational synthesis of heterostructured nanoparticles. By introducing copper sulfide nanorods into mixtures of cations (Cd²⁺, Zn²⁺, Co²⁺, Ni²⁺, In³⁺, Ga³⁺) under purposely unoptimized conditions, many heterostructured metal sulfide products form simultaneously, maximizing product diversity. By modulating simple reaction variables, such as temperature, concentration, stoichiometry, choice of cations and morphology, we observe hundreds of products that are incompatible with existing design guidelines. We then translate these observations into scalable reactions to rationally produce high-yield samples with previously inaccessible features. [Figure not available: see fulltext.]