Metal Cation Valency Dependence in Morphology Evolution of Cu S Nanodisk Seeds and Their Pseudomorphic Cation Exchanges.

A crucial parameter in the design of semiconductor nanoparticles (NPs) with controllable optical, magnetic, electronic, and catalytic properties is the morphology. Herein, we demonstrate the potential of additive metal cations with variable valency to direct the morphology evolution of copper-deficient Cu S nanoparticles in the process of seed-mediated growth. In particular, the djurleite Cu S seed could evolve from disk into tetradecahedron in the presence of tin(IV) cations, whereas they merely formed sharp hexagonal nanodisks with tin(II) cations. In addition to djurleite Cu S, the tin(IV) cations could be generalized to direct the growth of roxbyite Cu S and covellite CuS nanodisk seeds into tetradecahedra. We further perform pseudomorphic cation exchanges of Cu S tetradecahedra with Zn and Cd to produce polyhedral zinc sulfide (ZnS) and cadmium sulfide (CdS) NPs. Moreover, we achieve Cu S/ZnS and Cu S/CdS tetradecahedral heterostructures via partial cation exchange, which are otherwise inaccessible by traditional synthetic approaches.