Versatile synthesis of yolk/shell hybrid nanocrystals via ion-exchange reactions for novel metal/semiconductor and semiconductor/semiconductor conformations

Yolk/shell (Y–S) hybrid nanoarchitectures, owing to the interior voids created for individualized catalyst applications, have emerged as new candidates for effectively isolating catalytic species. However, the well-defined hollow interiors with flexible core and shell compositions—such as noble-metal cores, metal-oxide cores, and widespread semiconductor shells—and a flexible anisotropic shape are far from the requirements. In particular, the introduction of catalytic noble metals or metal-oxide nanocrystals (NCs) with isotropic or anisotropic shapes into various hollow semiconductor structures with well-defined morphologies has been rarely reported but is urgently needed. Herein, we propose a strategy involving the careful sulfuration of as-prepared cavity-free core/shell NCs or metal-oxide NCs followed by phosphine-initialized cation-exchange reactions for preparing metal@semiconductor and metal oxide@semiconductor (II-VI) Y–S NCs. The geometry, size, and conformations of the core and shell are fully and independently considered. New and unprecendented metal@semiconductor and metal oxide@semiconductor (II-VI) Y–S NCs are prepared via widespread phosphine-initialized cation-exchange reactions.