Synthetic Deconvolution of Interfaces and Materials Components in Hybrid Nanoparticles

5 years ago

Synthetic Deconvolution of Interfaces and Materials Components in Hybrid Nanoparticles

Raymond E. Schaak, James M. Hodges, Julie L. Fenton

Interfaces between nanoscale solids can facilitate coupling between dissimilar materials, leading to emergent and synergistic properties as well as mix-and-match multifunctionality. Seeded-growth methods, whereby one material is grown directly off of the surface of another, can lead to the formation of hybrid nanoparticles containing such solid-state heterojunctions. Successfully applying seeded-growth methods to the synthesis of hybrid nanoparticles, however, requires a precise balance of competing reaction variables, which limits the scope of materials that can be routinely incorporated into them and, accordingly, the types of achievable interfaces. Here, we describe an alternate pathway that overcomes key limitations of seeded-growth methods by synthetically deconvoluting the formation of particle–particle interfaces and the incorporation of desired materials components. Readily accessible hybrid nanoparticles can be rationally modified using sequential anion and cation exchange reactions which transform them into derivative products that contain different constituent materials but retain the preprogrammed morphologies and interfaces. Using Pt–MnO heterodimers as a synthetic entryway, we demonstrate the synthesis of seven different derivative Pt–M_aX_y (M = metal, X = chalcogen) heterodimers through integrated ion exchange pathways. We also demonstrate that tunable domain sizes are retained during complete multistep material transformations and that partial exchanges can be used to introduce morphologically sophisticated features into hybrid nanoparticles, including core@shell components. The sequential ion exchange reactions can also be applied to different domains of three-component hybrid nanoparticles, demonstrated for the transformation of Fe₃O₄–Pt–MnO into FeS_x–Pt–Cu₂S. Finally, the hybrid nanoparticle ion exchange reactions proceed with retention of anion sublattice structure across the particle–particle interfaces, demonstrating that crystallographic orientation and domain alignment are preserved. Collectively, these results demonstrate the wide-ranging applicability of sequential ion exchange reactions to controllably access a diverse library of colloidal hybrid nanoparticles across a wide range of materials, morphologies, and interfaces.

Publisher URL: http://dx.doi.org/10.1021/acs.chemmater.7b02556

DOI: 10.1021/acs.chemmater.7b02556