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Nanocrystals of Lead Chalcohalides: A Series of Kinetically Trapped Metastable Nanostructures.

ABSTRACT: We report the colloidal synthesis of a series of surfactant-stabilized lead chalcohalide nanocrystals. Our work is mainly focused on Pb₄S₃Br₂, a chalcohalide phase unknown to date that does not belong to the ambient-pressure PbS-PbBr₂ phase diagram. The Pb₄S₃Br₂ nanocrystals herein feature a remarkably narrow size distribution (with a size dispersion as low as 5%), a good size tunability (from 7 to ?30 nm), an indirect bandgap, photoconductivity (responsivity = 4 ± 1 mA/W), and stability for months in air. A crystal structure is proposed for this new material by combining the information from 3D electron diffraction and electron tomography of a single nanocrystal, X-ray powder diffraction, and density functional theory calculations. Such a structure is closely related to that of the recently discovered high-pressure chalcohalide Pb₄S₃I₂ phase, and indeed we were able to extend our synthesis scheme to Pb₄S₃I₂ colloidal nanocrystals, whose structure matches the one that has been published for the bulk. Finally, we could also prepare nanocrystals of Pb₃S₂Cl₂, which proved to be a structural analogue of the recently reported bulk Pb₃Se₂Br₂ phase. It is remarkable that one high-pressure structure (for Pb₄S₃I₂) and two metastable structures that had not yet been reported (for Pb₄S₃Br₂ and Pb₃S₂Cl₂) can be prepared on the nanoscale by wet-chemical approaches. This highlights the important role of colloidal chemistry in the discovery of new materials and motivates further exploration into metal chalcohalide nanocrystals.

SUBMITTER: Toso S

PROVIDER: S-EPMC7737912 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature

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Nanocrystals of Lead Chalcohalides: A Series of Kinetically Trapped Metastable Nanostructures.

Toso Stefano S Akkerman Quinten A QA Martín-García Beatriz B Prato Mirko M Zito Juliette J Infante Ivan I Dang Zhiya Z Moliterni Anna A Giannini Cinzia C Bladt Eva E Lobato Ivan I Ramade Julien J Bals Sara S Buha Joka J Spirito Davide D Mugnaioli Enrico E Gemmi Mauro M Manna Liberato L

Journal of the American Chemical Society 20200521 22

We report the colloidal synthesis of a series of surfactant-stabilized lead chalcohalide nanocrystals. Our work is mainly focused on Pb4S3Br2, a chalcohalide phase unknown to date that does not belong to the ambient-pressure PbS-PbBr2 phase diagram. The Pb4S3Br2 nanocrystals herein feature a remarkably narrow size distribution (with a size dispersion as low as 5%), a good size tunability (from 7 to ∼30 nm), an indirect ...[more]

PMID: 32374173

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Dataset Information

Nanocrystals of Lead Chalcohalides: A Series of Kinetically Trapped Metastable Nanostructures.

Publications

Nanocrystals of Lead Chalcohalides: A Series of Kinetically Trapped Metastable Nanostructures.

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