The electronic structure of the metal–organic interface of isolated ligand coated gold nanoparticles

Schürmann, Robin; Titov, Evgenii; Ebel, Kenny; Kogikoski, Sergio; Mostafa, Amr; Saalfrank, Peter; Milosavljević, Aleksandar R.; Bald, Ilko

doi:10.1039/d1na00737h

Cited by 9 publications

(7 citation statements)

References 80 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By comparing the values of the ionization energies obtained by these two techniques, the estimated value of the work function (ϕ) of Ag–Bi–I nanoplatelets was found to be 4.7 eV. It should be noted, however, that in the XAPS of isolated nanoparticles, the near-surface vacuum level cannot be perfectly defined, which results in additional uncertainty in the determination of the ionization energy. , …”

Section: Resultsmentioning

confidence: 99%

“…It should be noted, however, that in the XAPS of isolated nanoparticles, the near-surface vacuum level cannot be perfectly defined, which results in additional uncertainty in the determination of the ionization energy. 64,65 The optical properties of the Ag−Bi−I powder and the colloidal dispersion in acetonitrile are presented in Figure 5. The diffuse reflectance spectrum of the Ag−Bi−I powder samples (dashed black line) displays an onset of absorption at 732 nm (∼1.7 eV), which is a typical value for the band gap of Ag−Bi−I thin films and powder samples.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Electronic Properties of Silver–Bismuth Iodide Rudorffite Nanoplatelets

et al. 2022

Self Cite

View full text Add to dashboard Cite

Silver−bismuth iodide (Ag−Bi−I) rudorffites are chemically stable and non-toxic materials that can act as a possible lead-free replacement for methylammonium lead halides in optoelectronic applications. We report on a simple route for fabricating Ag−Bi−I colloidal nanoplatelets approximately 160 nm in lateral dimensions and 1−8 nm in thickness via exfoliation of Ag−Bi−I rudorffite powders in acetonitrile. The valence band electronic structure of isolated Ag−Bi−I nanoplatelets was investigated using synchrotron radiation to perform X-ray aerosol photoelectron spectroscopy (XAPS). The ionization energy of the material was found to be 6.1 ± 0.2 eV with respect to the vacuum level. UV−vis absorption and photoluminescence spectroscopies of the Ag−Bi−I colloids showed that the optical properties of the nanoplatelets originate from I 5p to Bi 6p and I 5p to I 5p transitions, which is further confirmed by density functional theory (DFT) calculations. Finally, calculations based on the DFT and k • p theoretical methods showed that the quantum confinement effect is very weak in the system studied.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

Electronic Properties of Silver–Bismuth Iodide Rudorffite Nanoplatelets

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…Second, the local concentration of reagents may also vary from one NP to another due to variations in the local surface charge of the substrate or the differently sized NPs under illumination. [51][52][53] Third, for this particular reaction the age of the gold precursor is also an important parameter, [54] further compromising the reproducibility of the growing kinetics.…”

Section: Resultsmentioning

confidence: 99%

Fine Tuning the Optical Properties of Single Au Nanoparticles by Plasmon‐Driven Growth in Closed‐Loop Control

Martínez

Gargiulo

Barella

et al. 2022

Advanced Optical Materials

View full text Add to dashboard Cite

patterns. However, they are limited in terms of combining materials, the typical crystallinity of the materials is usually poor, and 3D geometries such as spheres, nanostars, or core-shells are impossible or impractical to obtain. Electrochemical growth of NPs allows the fabrication of 3D geometries such as nanoflowers, but with limited possibilities of pattern design, material combination, and choice of substrate. [14][15][16] On the other hand, colloidal chemistry offers enormous versatility to obtain NPs with different shapes, compositions, and sizes by modulating the synthesis conditions. [17,18] Plasmon-driven reactions use light as an additional degree of freedom to tune the final morphology and size of colloidal metallic NPs. [19] For example, plasmon-driven reduction of Ag + has been used to produce colloidal Ag NPs of various shapes from Ag spherical seeds, [20,21] as well as Au@Ag coreshell NPs from Au seeds. [22] Then, the challenge of how to bring the colloidal NPs from the liquid phase to specific positions of a substrate remains.The simplest way to attach colloidal NPs to substrates is through electrostatic deposition, but obtaining ordered arrays is not possible this way. [23] Ordered arrays of NPs can be obtained by self-assembly methods, but the versatility is limited to their thermodynamically most stable configurations. [24] Templateassisted self-assembly adds flexibility of pattern design but requires additional steps than lengthen and complicate the fabrication procedure. [25,26] Maximum flexibility can be obtained by methods that utilize an AFM tip [27] or focused laser light [28] to drive deposition in specific regions of the substrate. In general, combining different NPs with all these methods remains a challenge.An emerging method to deposit colloidal NPs in predefined positions of a substrate with high accuracy and flexibility of pattern design is optical printing. [29][30][31][32][33][34] The technique is based on optical forces and allows the printing of virtually any kind of NP that interacts with light. This technique is also able to selectively print subpopulations of NPs out of a polydisperse suspension. [33,35] An appealing route for tailoring the optical properties of individual supported NPs is to perform controlled plasmondriven growth reactions on them. For example, the reduction of silver ions on Ag NPs, [36] the reduction of aqueous PtCl 4 2− on Au NPs, [37] and the copper oxide reduction on Cu NPs [38] were demonstrated by this approach. Also, supported Au nanoprisms,The morphology and composition of metallic nanoparticles (NPs) determine their optical response, so finely controlling them at the single particle level is the key to achieve tailored functionalities. Here, the control of plasmondriven growth of Au NPs is studied by live monitoring their photoluminescence emission in a closed-loop. It is found that the final emission maximum of single NPs can be tuned between 550 and 580 nm with a precision of 2-3 nm, and that the tuning is also reflected in their scattering ma...

show abstract

“…Surface ligands play an indispensable role in the formation and stabilization of colloidal inorganic NCs. , They are essential during crystal growth in solution and are necessary for maintaining post-synthetic NC stability. Beyond these foundational roles, surface ligands also serve as active modulators of NCs’ physicochemical properties, − thereby expanding their applicability across diverse fields such as heterogeneous catalysis, biomedical imaging, and surface-enhanced spectroscopy . While it has long been believed that surface ligands might impede catalytic activities, recent studies have upended this view by showing that these ligands can actually boost catalytic efficiencies and enhance product selectivity, , particularly in plasmon-enhanced photocatalysis. − …”

Section: Introductionmentioning

confidence: 99%

Nanoimaging of Water Bending and Carboxylate Stretching Modes in Colloidal Nanocrystal Films

Takele,

Habteyes

2024

J. Phys. Chem. C

View full text Add to dashboard Cite

In this study, we utilize scattering-type scanning near-field optical microscopy combined with a tunable infrared quantum cascade laser to achieve nanoscale imaging of vibrational modes within colloidal nanocrystal films under ambient conditions. We focus on the characterization of the bending mode of water and the stretching modes of carboxylates in films composed of gold nanocrystals (AuNCs) coated with trisodium citrate (Na 3 Cit) ligands. Our approach enables the spatial resolution of vibrational spectra, revealing a line width for the water bending mode of less than 3 cm −1 , a value notably consistent with that found in gasphase spectra. Intriguingly, our detailed analysis of the near-field spectra discriminates among three overlapping domains: the film− air interface, the internal layers of the film, and the film−substrate boundary. Further investigation into the citrate stretching modes elucidates three structural domains differentiated by their spatial relation to the AuNCs and the film's thickness. Our results challenge previous understandings by demonstrating that a particular vibrational band, formerly attributed to surface-bound carboxylates, is in fact a signature of higher-order structures in dense Na 3 Cit aggregates. Complementary surface-enhanced Raman spectroscopy measurements indicate that citrate's interaction with the nanocrystal surface is intricately modulated by sodium ions and water molecules. These experimental observations are further supported and explained by theoretical insights from density functional theory calculations. Collectively, our findings not only present a more nuanced view of the interactions within these complex nanoscale systems but also pave the way for a deeper understanding of surface chemistry and interfacial phenomena at the molecular level.

show abstract

The electronic structure of the metal–organic interface of isolated ligand coated gold nanoparticles

Abstract: Light induced electron transfer reactions of molecules on the surface of noble metal nanoparticles (NPs) depend significantly on the electronic properties of the metal–organic interface. Hybridized metal–molecule states and dipoles...

Cited by 9 publications

References 80 publications

Electronic Properties of Silver–Bismuth Iodide Rudorffite Nanoplatelets

Electronic Properties of Silver–Bismuth Iodide Rudorffite Nanoplatelets

Fine Tuning the Optical Properties of Single Au Nanoparticles by Plasmon‐Driven Growth in Closed‐Loop Control

Nanoimaging of Water Bending and Carboxylate Stretching Modes in Colloidal Nanocrystal Films

Contact Info

Product

Resources

About