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Bright, stable, and water-soluble CuInS2/ZnS nanocrystals passivated by cetyltrimethylammonium bromide.

Lee J, Han CS - Nanoscale Res Lett (2015)

Bottom Line: As the result, a high quantum yield (QY) of 56.0% and excellent photostability were acquired in aqueous media.For removing excessive surfactants, cold treatment (4°C) of the CTAB-water solution was adopted to prevent further agglomeration of CIS/ZnS NCs, which could secure high stability over 6 months (less 2% reduction in QY).The high stability and PL of water soluble CTAB-CIS/ZnS NCs suggest their potential in nanoelectronics and bioapplications.

View Article: PubMed Central - PubMed

Affiliation: School of Mechanical Engineering, Korea University, 145 Anam-ro, Seoul, Korea.

ABSTRACT
We report a highly bright and stable aqueous dispersion of CuInS2/ZnS (CIS/ZnS) nanocrystals (NCs) using surfactant-assisted microemulsion and cold treatment. CIS/ZnS NCs were facilely synthesized via a stepwise, consecutive hybrid flow reactor approach. To stabilize the optical properties of hydrophobic CIS/ZnS NCs, cetyltrimethylammonium bromide (CTAB) was chosen as a matrix for aqueous phase transfer. As the result, a high quantum yield (QY) of 56.0% and excellent photostability were acquired in aqueous media. For removing excessive surfactants, cold treatment (4°C) of the CTAB-water solution was adopted to prevent further agglomeration of CIS/ZnS NCs, which could secure high stability over 6 months (less 2% reduction in QY). The optical features and structure of the obtained CTAB stabilized CIS/ZnS (CTAB-CIS/ZnS) NCs have been characterized by UV-vis and photoluminescence (PL) spectroscopies, XRD, XPS, EDX, and TEM. The high stability and PL of water soluble CTAB-CIS/ZnS NCs suggest their potential in nanoelectronics and bioapplications.

No MeSH data available.


Schematic diagram and structural analysis of CIS/ZnS NCs. (a) Schematic diagram showing the hybrid flow reactor. (b) High-resolution TEM image of CIS/ZnS NCs. (c) X-ray diffraction pattern of CIS/ZnS NCs. (d) EDX spectrum of the CIS/ZnS NCs.
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Fig2: Schematic diagram and structural analysis of CIS/ZnS NCs. (a) Schematic diagram showing the hybrid flow reactor. (b) High-resolution TEM image of CIS/ZnS NCs. (c) X-ray diffraction pattern of CIS/ZnS NCs. (d) EDX spectrum of the CIS/ZnS NCs.

Mentions: The scheme of our hybrid flow reactor is shown in Figure 2a. The reactor is composed of two flask mixers, one pump and one furnace. Both flow rate and temperature can be controlled. Owing to the facileness of our stepwise, consecutive hybrid flow reactor approach, CIS/ZnS NCs are also readily scalable to a larger amount. This method can produce gram quantities of material with a chemical yield in excess of 90% with minimal solvent waste. The detailed experimental procedure is provided in the ‘Methods’ section. As shown in Figure 2b, the CIS/ZnS NCs were quasispherical particles with an average diameter of about 4 to 5 nm. The existence of well-resolved lattice planes in the inset of Figure 2b demonstrates the good crystallinity of the NCs; moreover, the lattice spacing between two adjacent planes was 0.357 nm. Figure 2c shows the XRD pattern of the as-prepared CIS/ZnS core/shell NCs. The powder patterns for CIS (red color) and ZnS (blue color) are also shown for comparison in the bottom to inset. The location of the pattern is in good agreement with the Joint Committee on Powder Diffraction Standards (JCPDS) reference diagrams in the bottom inset (JCPDS No. 32–0339: CuInS2 and 10–0434: ZnS). EDX measurement result shown in Figure 2d indicates that the NCs were composed of copper, indium, zinc, and sulfur elements.Figure 2


Bright, stable, and water-soluble CuInS2/ZnS nanocrystals passivated by cetyltrimethylammonium bromide.

Lee J, Han CS - Nanoscale Res Lett (2015)

Schematic diagram and structural analysis of CIS/ZnS NCs. (a) Schematic diagram showing the hybrid flow reactor. (b) High-resolution TEM image of CIS/ZnS NCs. (c) X-ray diffraction pattern of CIS/ZnS NCs. (d) EDX spectrum of the CIS/ZnS NCs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
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Fig2: Schematic diagram and structural analysis of CIS/ZnS NCs. (a) Schematic diagram showing the hybrid flow reactor. (b) High-resolution TEM image of CIS/ZnS NCs. (c) X-ray diffraction pattern of CIS/ZnS NCs. (d) EDX spectrum of the CIS/ZnS NCs.
Mentions: The scheme of our hybrid flow reactor is shown in Figure 2a. The reactor is composed of two flask mixers, one pump and one furnace. Both flow rate and temperature can be controlled. Owing to the facileness of our stepwise, consecutive hybrid flow reactor approach, CIS/ZnS NCs are also readily scalable to a larger amount. This method can produce gram quantities of material with a chemical yield in excess of 90% with minimal solvent waste. The detailed experimental procedure is provided in the ‘Methods’ section. As shown in Figure 2b, the CIS/ZnS NCs were quasispherical particles with an average diameter of about 4 to 5 nm. The existence of well-resolved lattice planes in the inset of Figure 2b demonstrates the good crystallinity of the NCs; moreover, the lattice spacing between two adjacent planes was 0.357 nm. Figure 2c shows the XRD pattern of the as-prepared CIS/ZnS core/shell NCs. The powder patterns for CIS (red color) and ZnS (blue color) are also shown for comparison in the bottom to inset. The location of the pattern is in good agreement with the Joint Committee on Powder Diffraction Standards (JCPDS) reference diagrams in the bottom inset (JCPDS No. 32–0339: CuInS2 and 10–0434: ZnS). EDX measurement result shown in Figure 2d indicates that the NCs were composed of copper, indium, zinc, and sulfur elements.Figure 2

Bottom Line: As the result, a high quantum yield (QY) of 56.0% and excellent photostability were acquired in aqueous media.For removing excessive surfactants, cold treatment (4°C) of the CTAB-water solution was adopted to prevent further agglomeration of CIS/ZnS NCs, which could secure high stability over 6 months (less 2% reduction in QY).The high stability and PL of water soluble CTAB-CIS/ZnS NCs suggest their potential in nanoelectronics and bioapplications.

View Article: PubMed Central - PubMed

Affiliation: School of Mechanical Engineering, Korea University, 145 Anam-ro, Seoul, Korea.

ABSTRACT
We report a highly bright and stable aqueous dispersion of CuInS2/ZnS (CIS/ZnS) nanocrystals (NCs) using surfactant-assisted microemulsion and cold treatment. CIS/ZnS NCs were facilely synthesized via a stepwise, consecutive hybrid flow reactor approach. To stabilize the optical properties of hydrophobic CIS/ZnS NCs, cetyltrimethylammonium bromide (CTAB) was chosen as a matrix for aqueous phase transfer. As the result, a high quantum yield (QY) of 56.0% and excellent photostability were acquired in aqueous media. For removing excessive surfactants, cold treatment (4°C) of the CTAB-water solution was adopted to prevent further agglomeration of CIS/ZnS NCs, which could secure high stability over 6 months (less 2% reduction in QY). The optical features and structure of the obtained CTAB stabilized CIS/ZnS (CTAB-CIS/ZnS) NCs have been characterized by UV-vis and photoluminescence (PL) spectroscopies, XRD, XPS, EDX, and TEM. The high stability and PL of water soluble CTAB-CIS/ZnS NCs suggest their potential in nanoelectronics and bioapplications.

No MeSH data available.