Modeling Molecular Orientation Effects in Dye-Coated Nanostructures Using a Thin-Shell Approximation of Mie Theory for Radially Anisotropic Media

Abstract

We here develop a thin-shell approximation of the Mie scattering problem for a spherical core–shell structure with radial anisotropy in the shell. The solution of the full anisotropic Mie theory requires the computation of Bessel functions of complex orders, which has severely limited its application to relevant problems. The proposed thin-shell approximation removes this hurdle and is of a similar complexity to the isotropic Mie theory. We show that the predictions agree with those of the full anisotropic theory for nanoparticles with a shell thickness of the order of 1 nm or less. The approximation is therefore of great relevance to calculations of the optical properties of adsorbed molecular monolayers, for example, the optical response of dye-coated nanoparticles. In this context, we also propose a simple effective medium shell model to account for the radial anisotropy of a dye layer arising from a preferred adsorption geometry, for example, in-plane or out-of-plane. We show that the model agrees with the predictions of a simple microscopic model, but provides additional insights on how the molecular orientation in the dye layer affects its interaction with the nanoparticle, for example, with plasmon resonance of metallic particles. These simple thin-shell approximation and effective medium anisotropic shell models pave the way for further theoretical understanding of orientation and anisotropic effects in the context of dye-plasmon resonance coupling.

Strongly Coupled W2C Atomic Nanoclusters on N/P‐Codoped Graphene for Kinetically Enhanced Sulfur Host

“…The S 2p spectrum for the W 2 C@N/P‐rGO‐2/S composite in Figure S9F (Supporting Information) describes a 2p 3/2 and 2p 1/2 spin–orbit splitting of 1.2 eV and an intensity ratio of ≈2:1 . The peak at 163.8 eV for S 2p 3/2 is somewhat lower than that of pristine elemental sulfur (164.0 eV), suggesting the likely presence of CS species . The minor shoulder peak at ≈168 eV could be attributed to the sulfate species formed by oxidation of sulfur in air …”

“…The peak at 163.8 eV for S 2p 3/2 is somewhat lower than that of pristine elemental sulfur (164.0 eV), suggesting the likely presence of CS species . The minor shoulder peak at ≈168 eV could be attributed to the sulfate species formed by oxidation of sulfur in air …”

Strong Surface Bonding of Polysulfides by Teflonized Carbon Matrix for Enhanced Performance in Room Temperature Sodium‐Sulfur Battery

“…The shift in the peak to a lower binding energy reconfirms the presence of the CS bond. A minor peak observed at 168.6 eV is due to the sulfate species formed due to the oxidation of sulfur in air …”

Optimized Catalytic WS2–WO3 Heterostructure Design for Accelerated Polysulfide Conversion in Lithium–Sulfur Batteries

“…[ 1–3 ] Apart from the insulating nature of sulfur and lithium sulfide (Li 2 S), the dissolution of lithium polysulfides (LiPSs) intermediates in the electrolyte and their shuttling from cathode to the anode are the main problems leading to the poor cycling stability for practical applications. Tremendous efforts have been devoted to tackling these problems by the physical confinement with nanostructured carbon materials [ 4–8 ] and the chemical adsorption with various noncarbon oxides/sulfides/nitrides. [ 9–16 ] However, the weak affinity of carbon‐based materials and the limited adsorption capacity of noncarbon materials toward polar LiPSs make these strategies fail to meet the high sulfur loading electrode and the long cycling process.…”