Cu<sub>2</sub>S/ZnS Heterostructured Nanorods: Cation Exchange vs. Solution–Liquid–Solid‐like Growth

Zhai, You; Shim, Moonsub

doi:10.1002/cphc.201500859

Cited by 16 publications

(37 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…■ PREPARATION OF CATION EXCHANGE SOLUTIONS Many metal salts are commercially available and have been used for cation exchange reactions. Certain counterions can impact cation exchange reactions, 54 although further work is required to fully understand their roles. We have encountered similar counterion effects, especially when attempting sequential partial cation exchange reactions in which multiple counterions are present.…”

Section: ■ Synthesis and Characterization Of Roxbyite Copper Sulfide ...mentioning

confidence: 99%

Experimental Insights into Partial Cation Exchange Reactions for Synthesizing Heterostructured Metal Sulfide Nanocrystals

et al. 2020

View full text Add to dashboard Cite

Nanocrystal cation exchange is a post-synthetic process that modifies the composition of a nanoparticle while maintaining other important characteristics, including morphology and crystal structure. Partial cation exchange reactions can be used to rationally synthesize heterostructured nanoparticles that contain two or more material segments. Increasingly complex heterostructured nanoparticles are accessible using multiple sequential cation exchange reactions, but achieving targeted structures in high yield requires careful consideration of synthetic parameters and chemical reactivity. Here, we discuss in detail the synthetic protocols used in two distinct partial cation exchange pathways that are differentiated based on the relative amounts of metal salt reagentsexcess vs stoichiometricthat are used during the reaction. Using a model system obtained through Zn 2+ exchange on roxbyite copper sulfide nanorods, we demonstrate how targeted products can be synthesized reproducibly. We show how small deviations in reaction conditions, such as temperature, time, and particle concentration, can significantly impact the outcome of these reactions. We highlight important chemical and physical hazards, issues that can be encountered when characterizing heterostructured nanoparticles, and troubleshooting suggestions for overcoming commonly encountered pitfalls. Clear and detailed descriptions of these aspects of partial cation exchange reactions are important for enabling widespread reproducibly and further development of the field.

show abstract

Section: ■ Synthesis and Characterization Of Roxbyite Copper Sulfide ...mentioning

confidence: 99%

Experimental Insights into Partial Cation Exchange Reactions for Synthesizing Heterostructured Metal Sulfide Nanocrystals

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Several synthetic strategies have been used in the quest for high-quality colloidal copper chalcogenide-based HNCs: (i) single-stage one-pot heating-up; (ii) multistage postsynthetic cation exchange; and (iii) multistage seeded growth. In the single-stage one-pot heating-up method, the HNCs are obtained by adding precursors of different components (either at once or sequentially) in the same reaction flask (e.g., Cu 2– x S/CuInS 2 − and Cu 2– x S/ZnS HNRs , ). Although this approach is appealing because of its simplicity, it offers limited control over the dimensions and heteroarchitecture of the product HNCs because of a number of unavoidable competing processes (e.g., formation of shells of mixed composition, homogeneous nucleation, etching, uncontrolled cation exchange, etc . )…”

Section: Introductionmentioning

confidence: 99%

Seeded Growth Combined with Cation Exchange for the Synthesis of Anisotropic Cu_2–xS/ZnS, Cu_2–xS, and CuInS₂ Nanorods

et al. 2020

View full text Add to dashboard Cite

Colloidal copper(I) sulfide (Cu2–x S) nanocrystals (NCs) have attracted much attention for a wide range of applications because of their unique optoelectronic properties, driving scientists to explore the potential of using Cu2–x S NCs as seeds in the synthesis of heteronanocrystals to achieve new multifunctional materials. Herein, we developed a multistep synthesis strategy toward Cu2–x S/ZnS heteronanorods. The Janus-type Cu2–x S/ZnS heteronanorods are obtained by the injection of hexagonal high-chalcocite Cu2–x S seed NCs in a hot zinc oleate solution in the presence of suitable surfactants, 20 s after the injection of sulfur precursors. The Cu2–x S seed NCs undergo rapid aggregation and coalescence in the first few seconds after the injection, forming larger NCs that act as the effective seeds for heteronucleation and growth of ZnS. The ZnS heteronucleation occurs on a single (100) facet of the Cu2–x S seed NCs and is followed by fast anisotropic growth along a direction that is perpendicular to the c-axis, thus leading to Cu2–x S/ZnS Janus-type heteronanorods with a sharp heterointerface. Interestingly, the high-chalcocite crystal structure of the injected Cu2–x S seed NCs is preserved in the Cu2–x S segments of the heteronanorods because of the high-thermodynamic stability of this Cu2–x S phase. The Cu2–x S/ZnS heteronanorods are subsequently converted into single-component Cu2–x S and CuInS2 nanorods by postsynthetic topotactic cation exchange. This work expands the possibilities for the rational synthesis of colloidal multicomponent heteronanorods by allowing the design principles of postsynthetic heteroepitaxial seeded growth and nanoscale cation exchange to be combined, yielding access to a plethora of multicomponent heteronanorods with diameters in the quantum confinement regime.

show abstract

“…This is most likely related to the difficulty in balancing the reactivities of multiple precursors and the high solid-state diffusion rates of all the cations involved in the CuInX 2 lattice. These difficulties have been circumvented in recent works by performing cation exchange (CE) in NC templates, which yielded a variety of otherwise inaccessible anisotropic HNCs, such as Cu 2– x S/CuInS 2 core/crown nanoplatelets, CuInSe 2 /CuInS 2 dot core/rod shell nanorods, axially segmented Cu 2– x S/ZnS, and Cu 2– x S/CuAS 2 (A = In, Ga) heteronanorods . CE-based protocols are however limited by the availability of suitable template NCs or HNCs, by the difficulty in completely removing the native cations, and by atom economy (and toxicity) considerations, particularly when using sequential CE protocols starting from Cd-based HNC templates.…”

Section: Introductionmentioning

confidence: 99%

Near-Infrared-Emitting CuInS₂/ZnS Dot-in-Rod Colloidal Heteronanorods by Seeded Growth

et al. 2018

View full text Add to dashboard Cite

Synthesis protocols for anisotropic CuInX2 (X = S, Se, Te)-based heteronanocrystals (HNCs) are scarce due to the difficulty in balancing the reactivities of multiple precursors and the high solid-state diffusion rates of the cations involved in the CuInX2 lattice. In this work, we report a multistep seeded growth synthesis protocol that yields colloidal wurtzite CuInS2/ZnS dot core/rod shell HNCs with photoluminescence in the NIR (∼800 nm). The wurtzite CuInS2 NCs used as seeds are obtained by topotactic partial Cu+ for In3+ cation exchange in template Cu2–xS NCs. The seed NCs are injected in a hot solution of zinc oleate and hexadecylamine in octadecene, 20 s after the injection of sulfur in octadecene. This results in heteroepitaxial growth of wurtzite ZnS primarily on the Sulfur-terminated polar facet of the CuInS2 seed NCs, the other facets being overcoated only by a thin (∼1 monolayer) shell. The fast (∼21 nm/min) asymmetric axial growth of the nanorod proceeds by addition of [ZnS] monomer units, so that the polarity of the terminal (002) facet is preserved throughout the growth. The delayed injection of the CuInS2 seed NCs is crucial to allow the concentration of [ZnS] monomers to build up, thereby maximizing the anisotropic heteroepitaxial growth rates while minimizing the rates of competing processes (etching, cation exchange, alloying). Nevertheless, a mild etching still occurred, likely prior to the onset of heteroepitaxial overgrowth, shrinking the core size from 5.5 to ∼4 nm. The insights provided by this work open up new possibilities in designing multifunctional Cu-chalcogenide based colloidal heteronanocrystals.

show abstract

Cu₂S/ZnS Heterostructured Nanorods: Cation Exchange vs. Solution–Liquid–Solid‐like Growth

Cited by 16 publications

References 45 publications

Experimental Insights into Partial Cation Exchange Reactions for Synthesizing Heterostructured Metal Sulfide Nanocrystals

Experimental Insights into Partial Cation Exchange Reactions for Synthesizing Heterostructured Metal Sulfide Nanocrystals

Seeded Growth Combined with Cation Exchange for the Synthesis of Anisotropic Cu_2–xS/ZnS, Cu_2–xS, and CuInS₂ Nanorods

Near-Infrared-Emitting CuInS₂/ZnS Dot-in-Rod Colloidal Heteronanorods by Seeded Growth

Contact Info

Product

Resources

About

Cu2S/ZnS Heterostructured Nanorods: Cation Exchange vs. Solution–Liquid–Solid‐like Growth

Cited by 16 publications

References 45 publications

Experimental Insights into Partial Cation Exchange Reactions for Synthesizing Heterostructured Metal Sulfide Nanocrystals

Experimental Insights into Partial Cation Exchange Reactions for Synthesizing Heterostructured Metal Sulfide Nanocrystals

Seeded Growth Combined with Cation Exchange for the Synthesis of Anisotropic Cu2–xS/ZnS, Cu2–xS, and CuInS2 Nanorods

Near-Infrared-Emitting CuInS2/ZnS Dot-in-Rod Colloidal Heteronanorods by Seeded Growth

Contact Info

Product

Resources

About

Cu₂S/ZnS Heterostructured Nanorods: Cation Exchange vs. Solution–Liquid–Solid‐like Growth

Seeded Growth Combined with Cation Exchange for the Synthesis of Anisotropic Cu_2–xS/ZnS, Cu_2–xS, and CuInS₂ Nanorods

Near-Infrared-Emitting CuInS₂/ZnS Dot-in-Rod Colloidal Heteronanorods by Seeded Growth