Region-Controlled Framework Interface Mediated Anion Exchange Chemical Transformation to Designed Metal Phosphosulfide Heteronanostructures.

Postsynthetic chemical transformation provides a powerful platform for creating heteronanostructures (HNs) with well-defined materials and interfaces that generate synergy or enhancement. However, it remains a synthetic bottleneck for the precise construction of HNs with increased degrees of complexity and more elaborate functions in a predictable manner. Herein, we define a general transformative protocol for metal phosphosulfide HNs based on tunable hexagonal Cu _1.81 S frameworks with corner-, edge- and face-controlled growth of Co ₂ P domains. The region-controlled Cu _1.81 S-Co ₂ P framework interfaces can serve as "kinetic barriers" in mediating the direction and rate between P and S anion exchange reactions, thus leading to a family of morphology and phase designed Cu ₃ P _{1- x} S _x -Co ₂ P HNs with hollow (branched, dotted and crown), porous and core-shell architectures. This study reveals the internal transformation mechanism between metal sulfide and phosphide nanocrystals, and opens up a new way for the rational synthesis of metastable HNs that are otherwise inaccessible.