Extracting Electronic Transition Bands of Adsorbates from Molecule–Plasmon Excitation Coupling

Abstract

The coupling between molecular electronic and particle plasmon excitations can result in various intriguing outcomes depending on how strongly or weakly the excitations couple to compete with their respective decay rates. In this work, using methylene blue and thionine dyes as model systems, we show that the electronic absorption band of resonant adsorbates can be determined with submonolayer sensitivity from the weak molecule−plasmon excitation coupling that results in the attenuation on the plasmonic absorption band. The extracted spectra are strongly similar to the absorption spectra of the corresponding molecules in solution, apart from the expected spectral red-shift and broadening. Interestingly, the adsorption isotherms determined on the basis of the magnitude of the attenuation correlate linearly with that determined from the adsorbate-induced plasmon resonance red-shift. The results demonstrate that in the weak coupling regimes the plasmon modes can be considered as an environment that supplies energy to and takes energy from the adsorbates.

Anions as Intermediates in Plasmon Enhanced Photocatalytic Reactions

“…The 0–0 and 0–1 transitions are identified by fitting two Gaussian functions indicated by the dashed green and blue lines, respectively, and the sum of the two functions (solid black line) fits the experimental data points very well. With respect to the absorption spectrum of MB in water (solid gray line), the spectrum of the adsorbate on gold is shifted to the red and broadened, which can be attributed to surface–molecule interaction . The molecular absorption spectrum is within the broad plasmon resonance of the Au NP aggregates (brown line).…”

“…In Figure a, the absorption spectrum of MB adsorbed on gold (determined as described in ref ) is shown by the open circles. The 0–0 and 0–1 transitions are identified by fitting two Gaussian functions indicated by the dashed green and blue lines, respectively, and the sum of the two functions (solid black line) fits the experimental data points very well.…”

“…With respect to the absorption spectrum of MB in water (solid gray line), the spectrum of the adsorbate on gold is shifted to the red and broadened, which can be attributed to surface−molecule interaction. 78 The molecular absorption spectrum is within the broad plasmon resonance of the Au NP aggregates (brown line). The vertical dashed lines in Figure 2 indicate some of the excitation laser wavelengths used in recent experiments that have revealed product selectivity of the N-demethylation depending on the adsorption condition.…”

Exact Symmetric Solutions of MHD Casson Fluid Using Chemically Reactive Flow with Generalized Boundary Conditions

“…They used the homotopy analysis method to calculate the governing equation and Mathematica software (Wolfram Mathematica, New Jersey, NJ, United State) to provide a graphical illustration of the velocity gradient, temperature, and concentration gradient of the Casson model. Although research on the Casson model is ongoing, we include some related studies based on heat transfer [25][26][27][28][29], fractional models of fluids with magnetic field [30][31][32][33][34][35][36][37][38][39][40], and some others [41][42][43][44][45][46][47][48][49][50][51][52][53][54] herein. Motivated by the above discussion, we analyzed an analytic solution of incompressible and magnetic Casson fluid subjected to temperature and concentration dependence within a porous-surfaced plate.…”

MHD Hybrid Nanofluid Flow Due to Rotating Disk with Heat Absorption and Thermal Slip Effects: An Application of Intelligent Computing

“…Many of the researchers used traditional deterministic techniques to solve various fluid dynamics problems including Joule heating, entropy generation, nanofluid and viscous dissipation [31][32][33][34], Molecular Sensitivity of Near-Field Vibrational Infrared Imaging [35], Capillary driven flow in nanochannels [36], application of MnO 2 -Fe 3 O 4 /CuO hybrid catalysts [37] and Molecule-Plasmon Excitation Coupling [38], and the solution of such problems through modern stochastic solution methods based on the artificial intelligence algorithm is innovative. Stochastic solution techniques based on artificial intelligence (AI) algorithms are better and efficient alternatives for various linear and non-linear mathematical models representing a variety of fluidic problems [39][40][41][42][43][44].…”