Spectroscopy of Sonoluminescence and Sonochemistry in Water Saturated with N 2 –Ar Mixtures
| Autor: | Warda Ben Messaoud, Temim Ouerhani, Rachel Pflieger, Sergey I. Nikitenko |
|---|---|
| Přispěvatelé: | Sonochimie dans les Fluides Complexes (LSFC), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA) |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Chemistry
Radical Analytical chemistry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Dissociation (chemistry) Spectral line 0104 chemical sciences Surfaces Coatings and Films Sonochemistry Sonoluminescence Excited state Materials Chemistry Molecule [CHIM]Chemical Sciences Physical and Theoretical Chemistry 0210 nano-technology Spectroscopy ComputingMilieux_MISCELLANEOUS |
| Zdroj: | Journal of Physical Chemistry B Journal of Physical Chemistry B, 2015, 119 (52), pp.15885-15891. ⟨10.1021/acs.jpcb.5b10221⟩ Journal of Physical Chemistry B, American Chemical Society, 2015, 119 (52), pp.15885-15891. ⟨10.1021/acs.jpcb.5b10221⟩ |
| ISSN: | 1520-6106 1520-5207 |
| DOI: | 10.1021/acs.jpcb.5b10221⟩ |
| Popis: | Sonoluminescence spectra in relation with sonochemical activity of water sparged with Ar/N2 gas mixtures were systematically studied at two ultrasonic frequencies (20 and 359 kHz). At 20 kHz, solely the molecular emission of OH (A(2)Σ(+)-X(2)Πi) is observed in addition to a broad continuum typical for multibubble sonoluminescence. On the contrary, at high frequency a second emission band is present around 336 nm which is assigned to the NH (A(3)Π-X(3)Σ(-)) system. In addition, the sonolysis of a 0.2 M NH3·H2O solution at 359 kHz in the presence of pure Ar yields the emission bands of NH (A(3)Π - X(3)Σ(-)) (336 nm) and NH (C(1)Π-A(1)Δ) (322 nm) systems confirming the sonochemical production of NH radicals. The N2 (C(3)Πu-B(3)Πg) emission band is absent at both frequencies. This uncommon phenomenon can be explained by the quenching of the N2 (C(3)Πu) excited state with water molecules inside the bubbles. The sonoluminescence of NH radicals at 359 kHz indicates more effective intrabubble dissociation of N2 molecules at high ultrasonic frequency compared to low-frequency (20 kHz) ultrasound. Its absence at 20 kHz may also be related to strong quenching, e.g., by water molecules. The kinetic study of the formation of principal sonochemical products (H2, H2O2, HNO3, HNO2) confirmed the more drastic conditions produced during bubble collapse at higher ultrasonic frequency. |
| Databáze: | OpenAIRE |
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