A5015030467- Atmospheric Ozone and Climate
- Astrophysics and Star Formation Studies
- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Physics Studies
- Atmospheric chemistry and aerosols
- Electron and X-Ray Spectroscopy Techniques
- nanoparticles nucleation surface interactions
- Molecular Spectroscopy and Structure
- Electrochemical Analysis and Applications
- Spectroscopy and Laser Applications
- Atomic and Molecular Physics
- Electronic and Structural Properties of Oxides
- X-ray Spectroscopy and Fluorescence Analysis
- Quantum, superfluid, helium dynamics
- Mass Spectrometry Techniques and Applications
- Electrostatics and Colloid Interactions
- Molecular Junctions and Nanostructures
- Force Microscopy Techniques and Applications
- Nonlinear Dynamics and Pattern Formation
- Surface and Thin Film Phenomena
- Electrohydrodynamics and Fluid Dynamics
- Atmospheric and Environmental Gas Dynamics
- Mechanical and Optical Resonators
- Photochemistry and Electron Transfer Studies
- Inorganic Fluorides and Related Compounds
Laboratoire de Chimie Physique - Matière et Rayonnement
2022-2025
Sorbonne Université
2017-2025
Centre National de la Recherche Scientifique
2017-2025
Fritz Haber Institute of the Max Planck Society
2021-2024
Université Paris Sciences et Lettres
2017-2023
Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères
2017-2023
Observatoire de Paris
2021
NTT Basic Research Laboratories
2016
Liquid–vapor interfaces, particularly those between aqueous solutions and air, drive numerous important chemical physical processes in the atmosphere environment. X-ray photoelectron spectroscopy is an excellent method for investigation of these interfaces due to its surface sensitivity, elemental specificity, possibility obtain information on depth distribution solute solvent species interfacial region. In this Perspective, we review progress that was made field over past decades discuss...
The interface of the oceans and aqueous aerosols with air drives many important physical chemical processes in environment, including uptake CO 2 by oceans.
We have investigated the surfactant properties of phenol in aqueous solution as a function pH and bulk concentration using liquid-jet photoelectron spectroscopy (LJ-PES) surface tension measurements.
Abstract The multi-phase oxidation of S(IV) plays a crucial role in the atmosphere, leading to formation haze and severe pollution episodes. We here contribute its understanding on molecular level by reporting experimentally determined p K values various tautomers reaction barriers for SO 2 pathways. Complementary state-of-the-art molecular-dynamics simulations reveal depletion bisulfite at low pH liquid-vapor interface, resulting different tautomer ratio interface compared bulk. On...
An electromechanical resonator is developed in which the dissipation can be dynamically eliminated. The resultant motional dynamics captured by Van der Pol equation of motion opens up possibility a Hopf bifurcation where mechanical resonance loses stability when eliminated and period-doubling bifurcations becomes negative. In this latter regime, spectral response characterised multi-stability spanning bandwidth that more than an order magnitude wider intrinsic linewidth it sustains peak...
The characterization of liquid-vapor interfaces at the molecular level is an important underpinning for a basic understanding fundamental heterogeneous processes in many areas, such as atmospheric science. Here we use X-ray photoelectron spectroscopy to study adsorption model surfactant, octanoic acid, water-gas interface. In particular, examine information contained angular distributions and show that about relative depth molecules functional groups within can be obtained from these...
We present a combined Langmuir–Pockels trough and ambient pressure X-ray photoelectron spectroscopy (APXPS) study of the compression stearic acid surfactant layers on neat water. Changes in packing density molecules are directly determined from C 1s O APXPS data. The experimental data fit with 2D model for coverage. Based results these proof-of-principle experiments, we discuss remaining challenges that need to be overcome future investigations role surfactants heterogeneous chemical...
Context. Methane is among the main components of ice mantles insterstellar dust grains, where it at start a rich solid-phase chemical network. Quantification photon-induced desorption yield these frozen molecules and understanding underlying processes necessary to accurately model observations evolution various regions interstellar medium. Aims. This study aims experimentally determining absolute photodesorption yields for CH4 molecule as function photon energy. The influence composition...
Astrophysical observations show complex organic molecules (COMs) in the gas phase of protoplanetary disks. X-rays emitted from central young stellar object (YSO) that irradiate interstellar ices disk, followed by ejection phase, are a possible route to explain abundances observed cold regions. This process, known as X-ray photodesorption, needs be quantified for methanol-containing ices. paper I focuses on case photodesorption pure methanol We aim at experimentally measuring yields and its...
Photodesorption from water-rich interstellar ice mantles is known to play an important role on the gas-to-ice ratio in stars and planet formation regions. Quantitative determination of photodesorption yields laboratory crucial astrochemical models. This study presents for first time, photon-energy dependence water samples vacuum-UV (VUV) range. Experiments have been performed with Surface Processes ICES (SPICES) setup coupled DESIRS beamline at SOLEIL synchrotron facility (St. Aubin,...
Electronic excitations near the surface of water ice lead to desorption adsorbed molecules, through a so far debated mechanism. A systematic study photon-induced indirect desorption, revealed by spectral dependence (7--13 eV), is conducted for Ar, Kr, ${\mathrm{N}}_{2}$, and CO on ${\mathrm{H}}_{2}\mathrm{O}$ or ${\mathrm{D}}_{2}\mathrm{O}$ amorphous ices. The mass isotopic increase intrinsic efficiency with photon energy all point mechanism induced collisions between adsorbates energetic...
ConspectusPhotoelectron spectroscopy (PES) is a powerful tool for the investigation of liquid–vapor interfaces, with applications in many fields from environmental chemistry to fundamental physics. Among aspects that have been addressed PES question how molecules and ions arrange distribute themselves within interface, is, first few nanometers into solution. This information crucial importance, instance, atmospheric chemistry, determine which species are exposed what concentration gas-phase...
Astrophysical observations show complex organic molecules (COMs) in the gas phase of protoplanetary disks. X-rays emitted from central young stellar object (YSO) that irradiate interstellar ices disk, followed by ejection phase, are a possible route to explain abundances observed cold regions. This process, known as X-ray photodesorption, needs be quantified for methanol-containing ices. We aim at experimentally measuring photodesorption yields methanol and its photo-products binary mixed...
Electron-stimulated desorption (ESD) of cryosorbed molecules on surfaces is a process relevance to fields as varied vacuum dynamics in accelerators and astrochemistry. While from such molecular systems induced by keV electrons fast ions has been extensively studied, the sub-keV electron regime comparatively little known. We measured quantified electron-stimulated ice (layers N$_2$, CO, CO$_2$, Ar H$_2$O/D$_2$O condensed at cryogenic temperatures) 150-2000 eV energy range. In this stopping...
The study and quantification of UV photon-induced desorption frozen molecules furthers our understanding the chemical evolution cold interstellar regions. Nitric oxide (NO) is an important intermediate species in both gas-phase solid-phase networks. In this work, we present quantitative measurements photodesorption a pure NO ice.We used tunable monochromatic synchrotron light DESIRS beamline SOLEIL facility near Paris to irradiate ices 6 - 13.6 eV range measured by quadrupole mass...
The determination of depth profiles across interfaces is primary importance in many scientific and technological areas. Photoemission spectroscopy principle well suited for this purpose, yet a quantitative implementation investigations liquid-vapor hindered by the lack understanding electron-scattering processes liquids. Previous studies have shown, however, that core-level photoelectron angular distributions (PADs) are altered depth-dependent elastic electron scattering can, thus, reveal...
Abstract In this paper, we present the results on Auger/photoelectron coincidence spectroscopy (APECS) of molecules—propanethiol and bovine serum albumin (BSA)-deposited a gold wire surface, using magnetic bottle electron time-of-flight spectrometer. Although study is preliminary conducted under low vacuum (∼10 −7 mbar) conditions in comparison to surface science standards, it demonstrates APECS methods high efficiency probing complex molecules. We also establish its versatility potential...
We report an investigation of X-ray induced desorption neutrals, cations and anions from CO ice. The neutral CO, by far the most abundant, is quantified discussed within context its application to astrochemistry. many different cations, including large up mass limit spectrometer, are observed. In contrast, only desorbing detected O$^-$ C$^-$. mechanisms all these species with aid their photodesorption spectrum. evolution absorption spectrum shows significant chemical modifications ice upon...
Nonthermal desorption from icy grains containing H2CO has been invoked to explain the observed gas phase abundances in protoplanetary disks (PPDs) and photon dominated regions (PDRs). Photodesorption is thought play a key role; however, no absolute measurement of photodesorption ices was performed up now, so that default value used current astrophysical models. As yields differ one molecule other, it crucial experimentally investigate ices. We measured wavelength-resolved pure ices, on top...
Abstract Molecules involved in solvation shells have properties differing from those of the bulk solvent, which can turn affect reactivity. Among key these molecules are their nature and electronic structure. Widely used tools to characterize this type property X-ray-based spectroscopies, which, however, usually lack capability selectively probe solvation-shell molecules. A class X-ray triggered “non-local” processes has recognized potential provide selectivity. Intermolecular Coulombic...
Low-energy-electron emission from resonant Auger final states via intermolecular Coulombic decay (RA-ICD) has been previously described as a promising scenario for controlling radiation damage medical purposes, but so far only observed in prototypical atomic and molecular van der Waals dimers clusters. Here, we report the experimental observation of RA-ICD aqueous solution. We show that solvated Ca$^{2+}$ ions, can be very efficiently controlled by tuning photon energy exciting X-rays to...
Core-excitation of water ice releases many different molecules and ions in the gas phase. Studying these desorbed species underlying desorption mechanisms can provide useful information on effects x-ray irradiation ice. We report a detailed study induced number neutral, cationic, anionic from amorphous solid water. discuss relative contributions Auger secondary electrons (x-ray electron stimulated desorption) initial excitation (direct as well role photochemistry. Anions are shown to desorb...