A rapid, high yield size-selective precipitation method for generating Au nanoparticles in organic solvents with tunably monodisperse size distributions and replaceable ligands

Gravelsins, Steven; Dhirani, Al-Amin

doi:10.1039/c7ra11177k

Cited by 5 publications

(7 citation statements)

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“…Au NPs were synthesized according to a modified Brust method 28 , 35 , 36 . 50 mL of 50 mM tetraoctylammonium bromide in toluene was added to 25 mL of 40 mM hydrogen tetrachloroaurate in water and stirred for roughly 20 min.…”

Section: Methodsmentioning

confidence: 99%

“…As synthesized Au NPs were subsequently size-selected 36 before use in X-NS fabrication. 0.042 g of dodecylamine (DDA) was added to 5 mL of stock NP solution, and left to sit for at least 30 min for ligand exchange to occur.…”

Section: Methodsmentioning

confidence: 99%

“…Figure 1 illustrates the method used to fabricate X-NS. The first step in nanosheet fabrication is the generation of an ordered Au NP monolayer using a Teflon ring apparatus 17 , 36 . A Teflon ring (~2.51 cm inner diameter, supported by two 1 mm thick glass slides on each side) is positioned within a glass well (~6 cm diameter and ~1.5 cm height) and slowly filled with deionized water until the water surface exhibits a slightly convex surface curvature (see Fig.…”

Section: Methodsmentioning

confidence: 99%

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Large emergent optoelectronic enhancement in molecularly cross-linked gold nanoparticle nanosheets

et al. 2022

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A central goal in molecular electronics and optoelectronics is to translate tailorable molecular properties to larger materials and to the device level. Here, we present a method to fabricate molecularly cross-linked, self-assembled 2D nanoparticle sheets (X-NS). Our method extends a Langmuir approach of self-assembling gold nanoparticle (NP) arrays at an air-water interface by replacing the liquid sub-phase to an organic solvent to enable cross-linking with organic molecules, and then draining the sub-phase to deposit films. Remarkably, X-NS comprising conjugated oligophenylene dithiol cross-linkers (HS-(C6H4)n-SH, 1 ≤ n ≤ 3) exhibit increasing conductance with molecule length, ~6 orders of magnitude enhancement in UV-Vis extinction coefficients, and photoconductivity with molecule vs. NP contributions varying depending on the excitation wavelength. Finite difference time domain (FDTD) analyses and control measurements indicate that these effects can be modeled provided the local complex dielectric constant is strongly modified upon cross-linking. This suggests quantum hybridization at a molecule–band (q-MB) level. Given the vast number of molecules and nano-building blocks available, X-NS have potential to significantly increase the range of available 2D nanosheets and associated quantum properties.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Large emergent optoelectronic enhancement in molecularly cross-linked gold nanoparticle nanosheets

et al. 2022

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“…This method has been used for narrowing the size-distribution of semiconductor nanoparticles and noble metal nanoparticles. 26 For example, Gravelsins et al used this technique for Au nanoparticles that are soluble in organic solvents. 26 …”

Section: Analytical Separation Techniques In Nanomaterials Research: ...mentioning

confidence: 99%

“… 26 For example, Gravelsins et al used this technique for Au nanoparticles that are soluble in organic solvents. 26 …”

Section: Analytical Separation Techniques In Nanomaterials Research: ...mentioning

confidence: 99%

Analytical separation techniques: toward achieving atomic precision in nanomaterials science

Krishnadas

Bürgi

2022

Nanoscale

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Colloidal Synthesis of Homogeneous Ge_1–x–ySi_ySn_x Nanoalloys with Composition-Tunable Visible to Near-IR Optical Properties

Spera,

Pate,

Spence

et al. 2023

Chem. Mater.

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Group IV alloy nanocrystals (NCs) are a class of direct energy gap semiconductors that show high elemental abundance, low to nontoxicity, and composition-tunable absorption and emission properties. These properties have distinguished Ge1–x Sn x NCs as intriguing materials for near-infrared (IR) optical studies. Achieving a material with efficient visible emission requires a modified class of group IV alloys, and the computational studies suggest that this can be achieved with Ge1–x–y Si y Sn x NCs. Herein, we report a colloidal strategy for the synthesis of bulk-like (10.3 ± 2.5–25.5 ± 5.3 nm) and quantum-confined (3.2 ± 0.6–4.2 ± 1.1 nm) Ge1–x–y Si y Sn x alloys that show strong size confinement effects and composition-tunable visible to near IR absorption and emission properties. This synthesis produces a homogeneous alloy with a diamond cubic Ge structure and tunable Si (0.9–16.1%) and Sn (1.8–14.9%) compositions, exceeding the equilibrium solubility of Sn (<1%) in crystalline Si and Ge. Raman spectra of Ge1–x–y Si y Sn x alloys show a prominent red-shift of the Ge–Ge peak and the emergence of a Ge–Si peak with increasing Si/Sn, suggesting the growth of homogeneous alloys. The smaller Ge1–x–y Si y Sn x NCs exhibit absorption onsets from 1.21 to 1.94 eV for x = 1.8–6.8% and y = 0.9–16.1% compositions, which are blue-shifted from those reported for Ge1–x–y Si y Sn x bulk alloy films and Ge1–x Sn x alloy NCs, indicating the influence of Si incorporation and strong size confinement effects. Solid-state photoluminescence (PL) spectra reveal core-related PL maxima from 1.77–1.97 eV in agreement with absorption onsets, consistent with the energy gaps calculated for ∼3–4 nm alloy NCs. With a facile, low-temperature solution synthesis and direct control over physical properties, this methodology presents a noteworthy advancement in the synthesis of bulk-like and quantum-confined Ge1–x–y Si y Sn x alloys as versatile materials for future optical and electronic studies.

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A rapid, high yield size-selective precipitation method for generating Au nanoparticles in organic solvents with tunably monodisperse size distributions and replaceable ligands

Cited by 5 publications

References 24 publications

Large emergent optoelectronic enhancement in molecularly cross-linked gold nanoparticle nanosheets

Large emergent optoelectronic enhancement in molecularly cross-linked gold nanoparticle nanosheets

Analytical separation techniques: toward achieving atomic precision in nanomaterials science

Colloidal Synthesis of Homogeneous Ge_1–x–ySi_ySn_x Nanoalloys with Composition-Tunable Visible to Near-IR Optical Properties

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A rapid, high yield size-selective precipitation method for generating Au nanoparticles in organic solvents with tunably monodisperse size distributions and replaceable ligands

Cited by 5 publications

References 24 publications

Large emergent optoelectronic enhancement in molecularly cross-linked gold nanoparticle nanosheets

Large emergent optoelectronic enhancement in molecularly cross-linked gold nanoparticle nanosheets

Analytical separation techniques: toward achieving atomic precision in nanomaterials science

Colloidal Synthesis of Homogeneous Ge1–x–ySiySnx Nanoalloys with Composition-Tunable Visible to Near-IR Optical Properties

Contact Info

Product

Resources

About

Colloidal Synthesis of Homogeneous Ge_1–x–ySi_ySn_x Nanoalloys with Composition-Tunable Visible to Near-IR Optical Properties