Subsuming the Metal Seed to Transform Binary Metal Chalcogenide Nanocrystals into Multinary Compositions.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35593407.
- Also identified by DOI 10.1021/acsnano.1c11144 and PMC identifier 9245353.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Direct colloidal synthesis of multinary metal chalcogenide nanocrystals typically develops dynamically from the binary metal chalcogenide nanocrystals with the subsequent incorporation of additional metal cations from solution during the growth process. Metal seeding of binary and multinary chalcogenides is also established, although the seed is solely a catalyst for nanocrystal nucleation and the metal from the seed has never been exploited as active alloying nuclei. Here we form colloidal Cu-Bi-Zn-S nanorods (NRs) from Bi-seeded Cu<sub>2-<i>x</i></sub>S heterostructures. The evolution of these homogeneously alloyed NRs is driven by the dissolution of the Bi-rich seed and recrystallization of the Cu-rich stem into a transitional segment, followed by the incorporation of Zn<sup>2+</sup> to form the quaternary Cu-Bi-Zn-S composition. The present study also reveals that the variation of Zn concentration in the NRs modulates the aspect ratio and affects the nature of the majority charge carriers. The NRs exhibit promising thermoelectric properties with very low thermal conductivity values of 0.45 and 0.65 W/mK at 775 and 605 K, respectively, for Zn-poor and Zn-rich NRs. This study highlights the potential of metal seed alloying as a direct growth route to achieving homogeneously alloyed NRs compositions that are not possible by conventional direct methods or by postsynthetic transformations.