Cation Exchange:  A Simple and Versatile Route to Inorganic Colloidal Spheres with the Same Size but Different Compositions and Properties

Abstract

This paper describes a cation exchange approach to the synthesis of metal chalcogenide core-shell particles with the same size but a number of different compositions. This method begins with the preparation of colloidal spheres of amorphous Se (a-Se), followed by their reaction with Ag atoms to form Se@Ag2Se spheres. These core-shell spheres are then converted into Se@MSe (M = Zn, Cd, and Pb) via cation exchange with Zn2+, Cd2+, and Pb2+. All the colloidal spheres prepared using this method are monodispersed in size and characterized by a spherical shape and a smooth surface. Starting from the same batch of Se@Ag2Se, the resultant Se@MSe samples were essentially the same in size. Furthermore, these core-shell colloidal spheres can be easily made superparamagnetic by incorporating Fe3O4 nanoparticles into the a-Se cores. This synthetic approach provides a simple and versatile route to magnetoactive core-shell spheres with the same size but a range of different compositions. This study also implies that it is feasible to further increase the diversity of cations that can be used in the cation exchange of a colloidal system to produce multifunctional core-shell spheres with a variety of properties.

Hollow Micro‐/Nanostructures: Synthesis and Applications

“…[140][141][142][143] [144] and ZnX (X ¼ S, Se) hollow spheres based on sonochemical anionic exchange of ZnO nanospheres. [145] Starting with ZnSe hollow microspheres, Li and co-workers synthesized a series of chalcogenide and oxide semiconductor hollow microspheres by performing both anionic and cations exchange reactions with a solution or gas phase conversion process.…”

Cation Exchange: A Versatile Tool for Nanomaterials Synthesis

“…78 The 14 and Zn 2+ . 25,26 Furthermore, the mild reaction conditions attendant to most exchanges make it a particularly powerful strategy for accessing many nonequilibrium morphologies, crystal phases, and materials that are difficult to prepare by direct hot-injection methods. Control over the extent of the exchange reaction further extends the utility of cation exchange for accessing a wide variety of heterostructures and doped nanocrystals.…”

Synergistic synthesis of quasi-monocrystal CdS nanoboxes with high-energy facets

“…This strategy is defined as "synergistic reactions" to distinguish it from the commonly used synchronous reactions. It is noted that, on one hand, the cation exchange is well-known as a powerful approach for synthesizing nanostructures through the cation substitution within the anion frame, in which the product can generally preserve the crystal structure of the templates, even at the nanoscale 15,16 . On the other hand, the chemical etching is a common practice to remove the template or inner material and produce hollow nanostructures 4 .…”