Quantification of a PbClx Shell on the Surface of PbS Nanocrystals
Differences between the properties of PbS nanocrystals prepared using a large excess of PbCl2 and those prepared using other Pb sources have led to speculation that a thin PbClx shell may be present on the surface of PbCl2-derived PbS nanocrystals. However, characterization of this chloride layer ha...
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| Format: | Article |
| Language: | English |
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American Chemical Society (ACS)
2020
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| Online Access: | https://hdl.handle.net/1721.1/123840 |
| _version_ | 1826206181380587520 |
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| author | Winslow, Samuel W. Liu, Yun Swan, James W Tisdale, William |
| author2 | Massachusetts Institute of Technology. Department of Chemical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Chemical Engineering Winslow, Samuel W. Liu, Yun Swan, James W Tisdale, William |
| author_sort | Winslow, Samuel W. |
| collection | MIT |
| description | Differences between the properties of PbS nanocrystals prepared using a large excess of PbCl2 and those prepared using other Pb sources have led to speculation that a thin PbClx shell may be present on the surface of PbCl2-derived PbS nanocrystals. However, characterization of this chloride layer has proven to be challenging because of the poor contrast provided by electron and X-ray scattering probes. Here, we show that small-angle neutron scattering (SANS) provides the compositional sensitivity needed to unambiguously quantify the PbClx shell that is present on the surface of PbCl2-derived PbS nanocrystals. Using a charge-balanced structural model, the scattering contribution of a ∼0.3 nm thick surface PbClx layer is parsed separately from ligand carboxylate head groups and PbS in the core. Global fitting of the SANS data across a solvent deuteration series enables unique determination of the spatial distribution of each material. These results are corroborated by quantitative nuclear magnetic resonance (NMR) and energy-dispersive X-ray spectroscopy (EDS). This work resolves a discrepancy in reported sizing curves for PbS nanocrystals prepared by different syntheses and further demonstrates the power of SANS in resolving molecular structure in soft and hybrid nanomaterials. Keyword: Quantum dots; Ligands; Layers; Solvents Nanocrystals |
| first_indexed | 2024-09-23T13:25:23Z |
| format | Article |
| id | mit-1721.1/123840 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T13:25:23Z |
| publishDate | 2020 |
| publisher | American Chemical Society (ACS) |
| record_format | dspace |
| spelling | mit-1721.1/1238402022-10-01T15:11:29Z Quantification of a PbClx Shell on the Surface of PbS Nanocrystals Winslow, Samuel W. Liu, Yun Swan, James W Tisdale, William Massachusetts Institute of Technology. Department of Chemical Engineering Differences between the properties of PbS nanocrystals prepared using a large excess of PbCl2 and those prepared using other Pb sources have led to speculation that a thin PbClx shell may be present on the surface of PbCl2-derived PbS nanocrystals. However, characterization of this chloride layer has proven to be challenging because of the poor contrast provided by electron and X-ray scattering probes. Here, we show that small-angle neutron scattering (SANS) provides the compositional sensitivity needed to unambiguously quantify the PbClx shell that is present on the surface of PbCl2-derived PbS nanocrystals. Using a charge-balanced structural model, the scattering contribution of a ∼0.3 nm thick surface PbClx layer is parsed separately from ligand carboxylate head groups and PbS in the core. Global fitting of the SANS data across a solvent deuteration series enables unique determination of the spatial distribution of each material. These results are corroborated by quantitative nuclear magnetic resonance (NMR) and energy-dispersive X-ray spectroscopy (EDS). This work resolves a discrepancy in reported sizing curves for PbS nanocrystals prepared by different syntheses and further demonstrates the power of SANS in resolving molecular structure in soft and hybrid nanomaterials. Keyword: Quantum dots; Ligands; Layers; Solvents Nanocrystals 2020-02-21T20:01:38Z 2020-02-21T20:01:38Z 2019-06 2019-06 2020-02-19T14:16:33Z Article http://purl.org/eprint/type/JournalArticle 2639-4979 2639-4979 https://hdl.handle.net/1721.1/123840 Winslow, Samuel W. et al. "Quantification of a PbClx Shell on the Surface of PbS Nanocrystals." ACS Materials Letters 1, 2, (June 2019): 209-216 © 2019 American Chemical Society en http://dx.doi.org/10.1021/acsmaterialslett.9b00200 ACS Materials Lettters Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Chemical Society (ACS) ACS |
| spellingShingle | Winslow, Samuel W. Liu, Yun Swan, James W Tisdale, William Quantification of a PbClx Shell on the Surface of PbS Nanocrystals |
| title | Quantification of a PbClx Shell on the Surface of PbS Nanocrystals |
| title_full | Quantification of a PbClx Shell on the Surface of PbS Nanocrystals |
| title_fullStr | Quantification of a PbClx Shell on the Surface of PbS Nanocrystals |
| title_full_unstemmed | Quantification of a PbClx Shell on the Surface of PbS Nanocrystals |
| title_short | Quantification of a PbClx Shell on the Surface of PbS Nanocrystals |
| title_sort | quantification of a pbclx shell on the surface of pbs nanocrystals |
| url | https://hdl.handle.net/1721.1/123840 |
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