A mix-and-match toolkit Domain-Selective Exchanges ... · Sequential Exchange Reactions on Spheres...
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Tunable Intraparticle Frameworks for Creating Complex Heterostructured Nanoparticle Libraries Julie L. Fenton , Benjamin C. Steimle, Raymond E. Schaak Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, United States S Acknowledgements S Formation of an Intraparticle Framework We begin with three different morphologies of Cu 1.8 S: 0D spheres, 1D rods, and 2D plates. Under conditions that promote cation exchange with Zn 2+ and Cd 2+ , we intentionally arrest these reactions prior to the complete replacement of the Cu + cations, and observe the formation of new, embedded interfaces on multi-component ZnS–Cu 1.8 S or CdS– Cu 1.8 S nanostructures that maintain the silhouette of the initial seed particle. Adjusting the reaction time tunes the extent of reaction, resulting in a library of particles with a tunable intraparticle framework of interfaces. The differing behavior of ZnS and CdS is attributed to the close relationship between the Cu 1.8 S starting crystal structure and the wurtzite-type product phases, all of which contain a similar, hexagonal anion substructure. 1 S Integration of Additional Synthetic Steps The intraparticle frameworks produced in the first two steps of our process can be combined with a variety of existing nanosynthetic strategies, including orthogonal exchange reactions, selective deposition, and chemical etching. These steps allow integration of additional material components, as well as the ability to generate patchy, porous, and asymmetrically decorated architectures. 1 S Crystallographic Regioselectivity Observed Through Multiple Sequential Exchange Reactions on Spheres and Rods Using sequential, partial exchange reactions, we can produce distinct CdS–ZnS–Cu 1.8 S nanosphere and nanorod isomers, among the most complex ever reported. As additional domains are added, the observed exchange behaviors of Zn 2+ and Cd 2+ are still governed by a tendency to form low-strain interfaces between domains. On nanorods, the crystallographic preferences can be temporarily superseded by the characteristic surface energy differences present in anisotropic structures, resulting in initial tip exchange for both cations. 2 S Domain-Selective Exchanges Preserve Programmed Network of Interfaces By using exchange conditions that selectively replace the remaining Cu 1.8 S with Zn 2+ , Cd 2+ , Co 2+ , Mn 2+ , or Ni 2+ , we expand the library of integrated materials and accessible interfaces into our programmed frameworks to include ZnS, CdS, CoS, MnS, and Ni 9 S 8 . In so doing, we replace all of the remaining Cu 1.8 S on the particle, using this material as convenient, easily-synthesized synthons only to define the overall morphology of the structure. 1 A mix-and-match toolkit transforms simple nanoparticle synthons into complex derivatives DMR-1607135 S Contact Julie L. Fenton, Ph.D. Arnold O. Beckman Postdoctoral Fellow Northwestern University [email protected] @julielfenton to download the full paper Scan Complex heterostructured nanomaterials with precisely defined materials and interfaces are important for many applications. However, rationally incorporating such features into nanoparticles with rigorous morphology control remains a synthetic bottleneck, particularly for particles less than 100 nm in size. We define a modular divergent synthesis strategy that progressively transforms simple nanoparticle synthons into increasingly sophisticated products. Subsequent manipulation of these intraparticle frameworks yielded a library of 50+ distinct heterostructured metal sulfide derivatives, including particles that contain asymmetric, patchy, porous, and sculpted nanoarchitectures. This generalizable mix- and-match strategy provides predictable retrosynthetic pathways to complex nanoparticle features that are otherwise inaccessible. 1 Left: TEM images and EDS maps illustrating evolution of intraparticle frameworks as a function of reaction time. Right: Regions of EDS spectra showing evolution of elemental signatures over the course of the exchange process (top), Comparison of sulfur sublattice in parent and product crystal structures, highlighting similarities in spacings (bottom). In maps and spectra, red signals are copper, green are zinc, and blue are cadmium. Asymmetric Functionalization via Selective Growth Selective Cation Exchange Selective Etching for Tunable Porosity Etching + Exchange Sequential Partial Exchanges + Etching Cu 1.8 S–ZnS Cu 1.8 S–ZnS ZnS CdS– Cu 1.8 S–ZnS CdS–ZnS CdS–ZnS CdS–CoS– ZnS Ag 2 S–ZnS CdS–ZnS CdS– Cu 1.8 S–Pt CdS–Pt TEM images and EDS maps of selected intraparticle frameworks of various morphologies before and after second exchange reaction replaces all remaining Cu regions with Cd (blue), Zn (green), Co (purple), Mn (cyan), or Ni (orange). Interfaces and particle morphology both preserved in all cases. Cartoons illustrating the preferred cation exchange directions for Cd 2+ and Zn 2+ on Cu 1.8 S spheres and rods, which are observed in the isomers shown in EDS maps (Cu is red, Zn is green, Cd is blue). In anisotropic rods, Cd reacts first with the high-energy tip before reverting to the crystallographically-predicted pathway. 1 Fenton, J.L.; Steimle, B.C.; Schaak, R.E. Science, 2018, 360, 513-517. 2 Fenton, J.L.; Steimle, B.C.; Schaak, R.E. J. Am. Chem. Soc. 2018, 140, 6771-6775.
Transcript of A mix-and-match toolkit Domain-Selective Exchanges ... · Sequential Exchange Reactions on Spheres...
Tunable Intraparticle Frameworks for Creating Complex Heterostructured Nanoparticle Libraries
Julie L. Fenton, Benjamin C. Steimle, Raymond E. SchaakDepartment of Chemistry, The Pennsylvania State University,
University Park, Pennsylvania, United States
S
Acknowledgements
S
Formation of an Intraparticle FrameworkWe begin with three different morphologies of Cu1.8S: 0D spheres, 1D rods, and 2D plates. Under conditions that promote cation exchange with Zn2+ and Cd2+, we intentionally arrest these reactions prior to the complete replacement of the Cu+ cations, and observe the formation of new, embedded interfaces on multi-component ZnS–Cu1.8S or CdS–Cu1.8S nanostructures that maintain the silhouette of the initial seed particle. Adjusting the reaction time tunes the extent of reaction, resulting in a library of particles with a tunable intraparticle framework of interfaces. The differing behavior of ZnS and CdS is attributed to the close relationship between the Cu1.8S starting crystal structure and the wurtzite-type product phases, all of which contain a similar, hexagonal anion substructure.1
S
Integration of Additional Synthetic StepsThe intraparticle frameworks produced in the first two steps of our process can be combined with a variety of existing nanosynthetic strategies, including orthogonal exchange reactions, selective deposition, and chemical etching. These steps allow integration of additional material components, as well as the ability to generate patchy, porous, and asymmetrically decorated architectures.1
S
Crystallographic Regioselectivity Observed Through Multiple Sequential Exchange Reactions on Spheres and Rods
Using sequential, partial exchange reactions, we can produce distinct CdS–ZnS–Cu1.8S nanosphere and nanorod isomers, among the most complex ever reported. As additional domains are added, the observed exchange behaviors of Zn2+ and Cd2+ are still governed by a tendency to form low-strain interfaces between domains. On nanorods, the crystallographic preferences can be temporarily superseded by the characteristic surface energy differences present in anisotropic structures, resulting in initial tip exchange for both cations.2
S
Domain-Selective Exchanges Preserve Programmed Network of Interfaces
By using exchange conditions that selectively replace the remaining Cu1.8S with Zn2+, Cd2+, Co2+, Mn2+, or Ni2+, we expand the library of integrated materials and accessible interfaces into our programmed frameworks to include ZnS, CdS, CoS, MnS, and Ni9S8. In so doing, we replace all of the remaining Cu1.8S on the particle, using this material as convenient, easily-synthesized synthons only to define the overall morphology of the structure.1
A mix-and-match toolkittransforms simple nanoparticlesynthons into complexderivatives
DMR-1607135
S
ContactJulie L. Fenton, Ph.D.Arnold O. Beckman Postdoctoral FellowNorthwestern [email protected]
@julielfenton
to download the full paper
Scan
Complex heterostructured nanomaterials with precisely defined materials and interfaces are important for many applications. However, rationally incorporating such features into nanoparticles with rigorous morphology control remains a synthetic bottleneck, particularly for particles less than 100 nm in size. We define a modular divergent synthesis strategy that progressively transforms simple nanoparticle synthons into increasingly sophisticated products. Subsequent manipulation of these intraparticle frameworks yielded a library of 50+ distinct heterostructured metal sulfide derivatives, including particles that contain asymmetric, patchy, porous, and sculpted nanoarchitectures. This generalizable mix-and-match strategy provides predictable retrosynthetic pathways to complex nanoparticle features that are otherwise inaccessible.1
Left: TEM images and EDS maps illustrating evolution of intraparticle frameworks as a function of reaction time. Right: Regions of EDS spectra showing evolution of elemental signatures over the course of the exchange process (top), Comparison of sulfur sublattice in parent and product crystal structures, highlighting similarities in spacings (bottom). In maps and spectra, red signals are copper, green are zinc, and blue are cadmium.
Asymmetric Functionalization via
Selective Growth
Selective Cation Exchange
Selective Etching for Tunable Porosity
Etching + Exchange
Sequential Partial Exchanges +
Etching
Cu1.8S–ZnSCu1.8S–ZnS ZnS CdS–
Cu1.8S–ZnS CdS–ZnS
CdS–ZnS CdS–CoS–ZnS
Ag2S–ZnSCdS–ZnSCdS–
Cu1.8S–Pt CdS–Pt
TEM images and EDS maps of selected intraparticle frameworks of various morphologies before and after second exchange reaction replaces all remaining Cu regions with Cd (blue), Zn (green), Co (purple), Mn (cyan), or Ni (orange). Interfaces and particle morphology both preserved in all cases.
Cartoons illustrating the preferred cation exchange directions for Cd2+ and Zn2+ on Cu1.8S spheres and rods, which are observed in the isomers shown in EDS maps (Cu is red, Zn is green, Cd is blue). In anisotropic rods, Cd reacts first with the high-energy tip before reverting to the crystallographically-predicted pathway.1 Fenton, J.L.; Steimle, B.C.; Schaak, R.E. Science, 2018, 360, 513-517. 2 Fenton, J.L.; Steimle, B.C.; Schaak, R.E. J. Am. Chem. Soc. 2018, 140, 6771-6775.
