Precoordination-directed synthesis of high-entropy perovskite colloidal nanocrystals

Abstract Perovskite nanocrystals (PNCs) are solution-processable quantum materials with defect tolerance, tunable electronic structures and strong light-matter interactions, enabling applications in optoelectronics and photocatalysis. Integrating high-entropy configurations into PNCs unlocks a vast chemical space for multicomponent synergy and functional expansion beyond conventional stoichiometry. However, their synthesis has been fundamentally constrained by mismatched multi-precursor kinetics and a trade-off between entropic stabilization and enthalpic phase segregation. Here we report a precoordination-directed strategy for the colloidal synthesis of high-entropy vacancy-ordered double perovskite nanocrystals with high phase purity, near-equimolar stoichiometry and elemental homogeneity. We show that the participation of excess chloride energetically encourages the formation of well-defined metal-halide octahedral units in the precursor, thereby promoting the topological conversion to a high-entropy double-perovskite phase after hot-injection. The elemental synergy of high-entropy PNCs renders them versatile catalysts, delivering ~ 14-fold improvement in photocatalytic coupling of benzyl alcohol to hydrobenzoin, ~ 17-fold in oxidative coupling of methane to ethane, and ~ 35-fold in oxidation of toluene to benzaldehyde, relative to their low-entropy analogues.