1
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Danilović D, Nahon L, Garcia GA, Milosavljević AR, Vukmirović N, Dojčilović R, Tošić D, Djoković V, Božanić DK. Velocity Map Imaging Photoelectron Spectroscopy of Silver Iodide Aerosol Particles. Chemphyschem 2024; 25:e202400328. [PMID: 38804589 DOI: 10.1002/cphc.202400328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/10/2024] [Accepted: 05/28/2024] [Indexed: 05/29/2024]
Abstract
The valence band electronic structure of isolated silver iodide nanoparticles (AgI NP) was investigated by vacuum-ultraviolet aerosol photoelectron spectroscopy using the velocity map imaging technique (VUV VMI-PES). The VUV VMI-PES results were obtained for polydisperse aerosol produced by aggregation of hydrocolloid of silver iodide particles 8-15 nm in size. The ionization energy of the AgI particles was found to be 6.0±0.1 eV with respect to the vacuum level. The DFT calculations showed that the main contribution to the density of AgI electronic states in the valence region originates from I 5p orbitals. The dependence of the asymmetry parameter on the electron energy showed that the value of the characteristic energy loss of excited photoelectrons was 2.7 eV, which coincided with the band gap of the nanomaterial.
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Affiliation(s)
- Danijela Danilović
- Center of Excellence for Photoconversion, Vinča Institute of Nuclear Sciences - National Institute of Republic of Serbia, University of Belgrade, P.O. Box 522, 11001, Belgrade, Serbia
| | - Laurent Nahon
- Synchrotron SOLEIL St. Aubin, BP48, 91192, Gif sur Yvette Cedex, France
| | - Gustavo A Garcia
- Synchrotron SOLEIL St. Aubin, BP48, 91192, Gif sur Yvette Cedex, France
| | | | - Nenad Vukmirović
- Institute of Physics Belgrade, University of Belgrade, Pregrevica118, 11080, Belgrade, Serbia
| | - Radovan Dojčilović
- Center of Excellence for Photoconversion, Vinča Institute of Nuclear Sciences - National Institute of Republic of Serbia, University of Belgrade, P.O. Box 522, 11001, Belgrade, Serbia
| | - Dragana Tošić
- Center of Excellence for Photoconversion, Vinča Institute of Nuclear Sciences - National Institute of Republic of Serbia, University of Belgrade, P.O. Box 522, 11001, Belgrade, Serbia
| | - Vladimir Djoković
- Center of Excellence for Photoconversion, Vinča Institute of Nuclear Sciences - National Institute of Republic of Serbia, University of Belgrade, P.O. Box 522, 11001, Belgrade, Serbia
| | - Dušan K Božanić
- Center of Excellence for Photoconversion, Vinča Institute of Nuclear Sciences - National Institute of Republic of Serbia, University of Belgrade, P.O. Box 522, 11001, Belgrade, Serbia
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2
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Preger C, Rissler J, Kivimäki A, Eriksson AC, Walsh N. A versatile sample-delivery system for X-ray photoelectron spectroscopy of in-flight aerosols and free nanoparticles at MAX IV Laboratory. JOURNAL OF SYNCHROTRON RADIATION 2024; 31:1382-1392. [PMID: 39110676 PMCID: PMC11371056 DOI: 10.1107/s1600577524005411] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 06/06/2024] [Indexed: 09/04/2024]
Abstract
Aerosol science is of utmost importance for both climate and public health research, and in recent years X-ray techniques have proven effective tools for aerosol-particle characterization. To date, such methods have often involved the study of particles collected onto a substrate, but a high photon flux may cause radiation damage to such deposited particles and volatile components can potentially react with the surrounding environment after sampling. These and many other factors make studies on collected aerosol particles challenging. Therefore, a new aerosol sample-delivery system dedicated to X-ray photoelectron spectroscopy studies of aerosol particles and gas molecules in-flight has been developed at the MAX IV Laboratory. The aerosol particles are brought from atmospheric pressure to vacuum in a continuous flow, ensuring that the sample is constantly renewed, thus avoiding radiation damage, and allowing measurements on the true unsupported aerosol. At the same time, available gas molecules can be used for energy calibration and to study gas-particle partitioning. The design features of the aerosol sample-delivery system and important information on the operation procedures are described in detail here. Furthermore, to demonstrate the experimental range of the aerosol sample-delivery system, results from aerosol particles of different shape, size and composition are presented, including inorganic atmospheric aerosols, secondary organic aerosols and engineered nanoparticles.
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Affiliation(s)
- C. Preger
- Ergonomics and Aerosol TechnologyLund UniversityBox 118221 00LundSweden
- MAX IV LaboratoryLund UniversityBox 118221 00LundSweden
- NanoLundLund UniversityBox 118221 00LundSweden
| | - J. Rissler
- Ergonomics and Aerosol TechnologyLund UniversityBox 118221 00LundSweden
- NanoLundLund UniversityBox 118221 00LundSweden
- RISE Research Institutes of SwedenScheelevägen 17223 70LundSweden
| | - A. Kivimäki
- MAX IV LaboratoryLund UniversityBox 118221 00LundSweden
| | - A. C. Eriksson
- Ergonomics and Aerosol TechnologyLund UniversityBox 118221 00LundSweden
- NanoLundLund UniversityBox 118221 00LundSweden
| | - N. Walsh
- MAX IV LaboratoryLund UniversityBox 118221 00LundSweden
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3
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Asmussen JD, Sishodia K, Bastian B, Abid AR, Ben Ltaief L, Pedersen HB, De S, Medina C, Pal N, Richter R, Fennel T, Krishnan S, Mudrich M. Electron energy loss and angular asymmetry induced by elastic scattering in superfluid helium nanodroplets. NANOSCALE 2023; 15:14025-14031. [PMID: 37559557 DOI: 10.1039/d3nr03295g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Helium nanodroplets are ideal model systems to unravel the complex interaction of condensed matter with ionizing radiation. Here we study the effect of purely elastic electron scattering on angular and energy distributions of photoelectrons emitted from He nanodroplets of variable size (10-109 atoms per droplets). For large droplets, photoelectrons develop a pronounced anisotropy along the incident light beam due to a shadowing effect within the droplets. In contrast, the detected photoelectron spectra are only weakly perturbed. This opens up possibilities for photoelectron spectroscopy of dopants embedded in droplets provided they are smaller than the penetration depth of the light and the trapping range of emitted electrons in liquid helium.
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Affiliation(s)
- Jakob D Asmussen
- Department of Physics and Astronomy, Aarhus University, Denmark.
| | - Keshav Sishodia
- Quantum Center of Excellence for Diamond and Emergent Materials and Department of Physics, Indian Institute of Technology Madras, India
| | - Björn Bastian
- Department of Physics and Astronomy, Aarhus University, Denmark.
| | - Abdul R Abid
- Department of Physics and Astronomy, Aarhus University, Denmark.
| | | | | | - Subhendu De
- Quantum Center of Excellence for Diamond and Emergent Materials and Department of Physics, Indian Institute of Technology Madras, India
| | | | | | | | | | - Sivarama Krishnan
- Quantum Center of Excellence for Diamond and Emergent Materials and Department of Physics, Indian Institute of Technology Madras, India
| | - Marcel Mudrich
- Department of Physics and Astronomy, Aarhus University, Denmark.
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4
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Ban L, Tang H, Yoder BL, Signorell R. Time-dependent photoemission from droplets: influence of size and charge on the photophysics near the surface. Faraday Discuss 2022; 236:461-484. [PMID: 35507329 PMCID: PMC9408814 DOI: 10.1039/d1fd00108f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/10/2022] [Indexed: 11/26/2022]
Abstract
Photoemission from submicrometer droplets containing a mixture of dioctyl phthalate and dioctyl sebacate was investigated by femtosecond and nanosecond photoionization. Photoelectron spectra recorded after ionization with single 4.7 eV femtosecond or nanosecond laser pulses showed marked differences between the two cases. These differences were attributed to ionization of long-lived states which only occurred within the duration of the nanosecond pulse. The tentative assignment of the long-lived states to dioctyl phthalate triplet states is discussed. A nanosecond-femtosecond pump-probe scheme using 4.7 eV (pump) and 3.1 eV (probe) pulses was used to investigate the decay dynamics of these long-lived states. The dynamics showed an accelerated decay rate at higher dioctyl phthalate concentrations. Furthermore, the dependence of the decay dynamics on droplet size and charge was investigated. The decay of the long-lived states was found to be faster in smaller droplets as well as in neutral droplets compared with both positively and negatively charged droplets. Possible mechanisms to explain these observations and the dominance of contributions from the droplets surface are discussed.
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Affiliation(s)
- Loren Ban
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland.
| | - Hanchao Tang
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland.
| | - Bruce L Yoder
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland.
| | - Ruth Signorell
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland.
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5
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Suchan J, Kolafa J, Slavíček P. Electron-induced fragmentation of water droplets: Simulation study. J Chem Phys 2022; 156:144303. [DOI: 10.1063/5.0088591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The transport of free electrons in a water environment is still poorly understood. We show that additional insight can be brought about by investigating fragmentation patterns of finite-size particles upon electron impact ionization. We have developed a composite protocol aiming to simulate fragmentation of water clusters by electrons with kinetic energies in the range of up to 100 eV. The ionization events for atomistically described molecular clusters are identified by a kinetic Monte Carlo procedure. We subsequently model the fragmentation with classical molecular dynamics simulations, calibrated by non-adiabatic quantum mechanics/molecular mechanics simulations of the ionization process. We consider one-electron ionizations, energy transfer via electronic excitation events, elastic scattering, and also the autoionization events through intermolecular Coulombic decay. The simulations reveal that larger water clusters are often ionized repeatedly, which is the cause of substantial fragmentation. After losing most of its energy, low-energy electrons further contribute to fragmentation by electronic excitations. The simultaneous measurement of cluster size distribution before and after the ionization represents a sensitive measure of the energy transferred into the system by an incident electron.
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Affiliation(s)
- Jiří Suchan
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 16628 Prague, Czech Republic
| | - Jiří Kolafa
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 16628 Prague, Czech Republic
| | - Petr Slavíček
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 16628 Prague, Czech Republic
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6
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Hartweg S, Garcia GA, Božanić DK, Nahon L. Condensation Effects on Electron Chiral Asymmetries in the Photoionization of Serine: From Free Molecules to Nanoparticles. J Phys Chem Lett 2021; 12:2385-2393. [PMID: 33660503 DOI: 10.1021/acs.jpclett.1c00258] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Structural changes at the molecular level, occurring at the onset of condensation, can be probed by angle-resolved valence photoelectron spectroscopy, which is inherently sensitive to the electronic structure. For larger condensed systems like aerosol particles, the observation of intrinsic angular anisotropies in photoemission (β parameters) is challenging due to the strong reduction of their magnitude by electron transport effects. Here, we use a less common, more sensitive observable in the form of the chiral asymmetry parameter to perform a comparative study of the VUV photoelectron spectroscopy and photoelectron circular dichroism (PECD) between pure gas phase enantiomers of the amino acid serine and their corresponding homochiral nanoparticles. We observe a relatively large (1%) and strongly kinetic energy-dependent asymmetry, discussed in terms of the emergence of local order and conformational changes potentially counterbalancing the loss of angular information due to electron transport scattering. This demonstrates the potential of PECD as a sensitive probe of the condensation effects from the gas phase to bulk-like chiral aerosol particles surpassing the potential of conventional photoemission observables such as β parameters.
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Affiliation(s)
- Sebastian Hartweg
- Synchrotron SOLEIL, l'Orme des Merisiers, Saint Aubin BP 48, 91192 Cedex, Gif sur Yvette, France
| | - Gustavo A Garcia
- Synchrotron SOLEIL, l'Orme des Merisiers, Saint Aubin BP 48, 91192 Cedex, Gif sur Yvette, France
| | - Dušan K Božanić
- Department of Radiation Chemistry and Physics, "VINČA" Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, 11001 Belgrade, Serbia
| | - Laurent Nahon
- Synchrotron SOLEIL, l'Orme des Merisiers, Saint Aubin BP 48, 91192 Cedex, Gif sur Yvette, France
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7
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Abstract
Intriguing properties of photoemission from free, unsupported particles and droplets were predicted nearly 50 years ago, though experiments were a technical challenge. The last few decades have seen a surge of research in the field, due to advances in aerosol technology (generation, characterization, and transfer into vacuum), the development of photoelectron imaging spectrometers, and advances in vacuum ultraviolet and ultrafast light sources. Particles and droplets offer several advantages for photoemission studies. For example, photoemission spectra are dependent on the particle's size, shape, and composition, providing a wealth of information that allows for the retrieval of genuine electronic properties of condensed phase. In this review, with a focus on submicrometer-sized, dielectric particles and droplets, we explain the utility of photoemission from such systems, summarize several applications from the literature, and present some thoughts on future research directions.
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Affiliation(s)
- Loren Ban
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland;
| | - Bruce L Yoder
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland;
| | - Ruth Signorell
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland;
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8
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Unger I, Saak CM, Salter M, Zieger P, Patanen M, Björneholm O. Influence of Organic Acids on the Surface Composition of Sea Spray Aerosol. J Phys Chem A 2020; 124:422-429. [PMID: 31833771 DOI: 10.1021/acs.jpca.9b09710] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent studies on sea spray aerosol indicate an enrichment of Ca2+ in small particles, which are often thought to originate from the very surface of a water body when bubbles burst. One model to explain this observation is the formation of ion pairs between Ca2+(aq) and surface-active organic species. In this study, we have used X-ray photoelectron spectroscopy to probe aqueous salt solutions and artificial sea spray aerosol to study whether ion pairing in the liquid environment also affects the surface composition of dry aerosol. Carboxylic acids were added to the sample solutions to mimic some of the organic compounds present in natural seawater. Our results show that the formation of a core-shell structure governs the surface composition of the aerosol. The core-shell structure contrasts previous observations of the dry sea spray aerosol on substrates. As such, this may indicate that substrates can impact the morphology of the dried aerosol.
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Affiliation(s)
- Isaak Unger
- Uppsala University , Box 516, SE-75120 Uppsala , Sweden
| | | | - Matthew Salter
- Uppsala University , Box 516, SE-75120 Uppsala , Sweden.,Department of Environmental Science and Analytical Chemistry , Stockholm University , SE-10691 Stockholm , Sweden.,Bolin Centre for Climate Research , SE-10691 Stockholm , Sweden
| | - Paul Zieger
- Department of Environmental Science and Analytical Chemistry , Stockholm University , SE-10691 Stockholm , Sweden.,Bolin Centre for Climate Research , SE-10691 Stockholm , Sweden
| | - Minna Patanen
- Nano and Molecular Systems Research Unit, Faculty of Science , University of Oulu , P.O. Box 8000 FI-90570 Oulu , Finland
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9
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Ban L, Gartmann TE, Yoder BL, Signorell R. Low-Energy Electron Escape from Liquid Interfaces: Charge and Quantum Effects. PHYSICAL REVIEW LETTERS 2020; 124:013402. [PMID: 31976689 DOI: 10.1103/physrevlett.124.013402] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Indexed: 05/27/2023]
Abstract
The high surface sensitivity and controlled surface charge state of submicron sized droplets is exploited to study low-energy electron transport through liquid interfaces using photoelectron imaging. Already a few charges on a droplet are found to modify the photoelectron images significantly. For narrow escape barriers, the comparison with an electron scattering model reveals pronounced quantum effects in the form of above-barrier reflections at electron kinetic energies below about 1 eV. The observed susceptibility to the characteristics of the electron escape barrier might provide access to these properties for liquid interfaces, which are generally difficult to investigate.
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Affiliation(s)
- Loren Ban
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland
| | - Thomas E Gartmann
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland
| | - Bruce L Yoder
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland
| | - R Signorell
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland
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10
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Jacobs MI, Xu B, Kostko O, Wiegel AA, Houle FA, Ahmed M, Wilson KR. Using Nanoparticle X-ray Spectroscopy to Probe the Formation of Reactive Chemical Gradients in Diffusion-Limited Aerosols. J Phys Chem A 2019; 123:6034-6044. [DOI: 10.1021/acs.jpca.9b04507] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Michael I. Jacobs
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Bo Xu
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Oleg Kostko
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Aaron A. Wiegel
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Frances A. Houle
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Kevin R. Wilson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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11
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Antonsson E, Gerke F, Merkel L, Halfpap I, Langer B, Rühl E. Size-dependent ion emission asymmetry of free NaCl nanoparticles excited by intense femtosecond laser pulses. Phys Chem Chem Phys 2019; 21:12130-12138. [PMID: 31140488 DOI: 10.1039/c9cp00696f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report on asymmetric ion emission of size-selected NaCl nanoparticles (d = 100-600 nm) ionized by intense femtosecond laser pulses (λ = 800 nm, peak intensity ∼1013 W cm-2). Velocity map imaging indicates that a higher ion yield is observed in the propagation direction of the laser pulses than in the opposite direction. This asymmetric ion emission is found to be size-dependent and increases with particle size. This pronounced size dependence is interpreted in terms of discrete dipole simulations of the internal electric field in the nanoparticles, which reveal that the internal field is enhanced in the forward propagation direction of the laser pulses, occurring for nanoparticles >100 nm. The ion emission asymmetry is further found to depend on the peak intensity of the laser radiation. Nanoparticles of 100 nm show a symmetric distribution of ion emission, while the ion emission for 600 nm particles is found to become increasingly symmetric as the peak intensity is increased. In addition to single pulse ionization experiments, we explore the angular distribution of ion emission of resonantly heated NaCl nanoparticles using a pump-probe setup. Here, ion emission is found to be more symmetric for resonantly heated nanoparticles than for single pulse excitation. These differences are explained by the absorption mechanism, where the probe pulse in a dual pulse experiment can be efficiently absorbed by plasmonic excitation for suitable delays between both laser pulses.
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Affiliation(s)
- E Antonsson
- Physical Chemistry, Freie Universität Berlin, Arnimallee 22, D-14195 Berlin, Germany.
| | - F Gerke
- Physical Chemistry, Freie Universität Berlin, Arnimallee 22, D-14195 Berlin, Germany.
| | - L Merkel
- Physical Chemistry, Freie Universität Berlin, Arnimallee 22, D-14195 Berlin, Germany.
| | - I Halfpap
- Physical Chemistry, Freie Universität Berlin, Arnimallee 22, D-14195 Berlin, Germany.
| | - B Langer
- Physical Chemistry, Freie Universität Berlin, Arnimallee 22, D-14195 Berlin, Germany.
| | - E Rühl
- Physical Chemistry, Freie Universität Berlin, Arnimallee 22, D-14195 Berlin, Germany.
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12
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13
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Winkler M, Børve KJ. Attenuation of slow (10-40 eV) electrons in soft nanoparticles: Size matters in argon clusters. Phys Rev E 2018; 97:012604. [PMID: 29448394 DOI: 10.1103/physreve.97.012604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Indexed: 06/08/2023]
Abstract
Electron attenuation due to inelastic and elastic scattering in condensed media can often be described in terms of the effective attenuation length (EAL) of the electron. The EAL is thus an important parameter for describing electron transport processes as exemplified by dissipation of energy following radiolysis. Focusing on electrons at low electron kinetic energies (10-40 eV) in condensed argon, we determine EAL from x-ray photoelectron spectra of argon nanoparticles and compare to values obtained from valence ionization in thin argon films as well as from gas-phase electron-scattering data. EAL determined from argon clusters shows variation with cluster size. Moreover, the values are significantly lower than those obtained in valence-ionization studies and from scattering data. Our results corroborate recent x-ray photoelectron spectroscopy-based determination of EALs of water showing large differences to the EALs determined by other methods in amorphous ice at low kinetic energies of the photoelectron [Y.-I. Suzuki, K. Nishizawa, N. Kurahashi, and T. Suzuki, Phys. Rev. E 90, 010302 (2014)PLEEE81539-375510.1103/PhysRevE.90.010302], underlining that care must be taken when using EAL values from other sources for core-level electrons.
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Affiliation(s)
- Mathias Winkler
- Department of Chemistry, University of Bergen, NO-5007 Bergen, Norway
| | - Knut J Børve
- Department of Chemistry, University of Bergen, NO-5007 Bergen, Norway
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14
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Heringa MF, Slowik JG, Goldmann M, Signorell R, Hemberger P, Bodi A. The Distant Double Bond Determines the Fate of the Carboxylic Group in the Dissociative Photoionization of Oleic Acid. Chemphyschem 2017; 18:3595-3604. [PMID: 28987011 DOI: 10.1002/cphc.201700983] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 09/30/2017] [Indexed: 11/10/2022]
Abstract
The valence threshold photoionization of oleic acid has been studied using synchrotron VUV radiation and imaging photoelectron photoion coincidence (iPEPICO) spectroscopy. An oleic acid aerosol beam was impacted on a copper thermodesorber, heated to 130 °C, to evaporate the particles quantitatively. Upon threshold photoionization, oleic acid produces the intact parent ion first, followed by dehydration at higher energies. Starting at ca. 10 eV, a large number of fragment ions slowly rise suggesting several fragmentation coordinates with quasi-degenerate activation energies. However, water loss is the dominant low-energy dissociation channel, and it is shown to be closely related to the unsaturated carbon chain. In the lowest-barrier process, one of the four allylic hydrogen atoms is transferred to the carboxyl group to form the leaving water molecule and a cyclic ketone fragment ion. A statistical model to analyze the breakdown diagram and measured rate constants yields a 0 K appearance energy of 9.77 eV, which can be compared with the density functional theory result of 9.19 eV. Alternative H-transfer steps yielding a terminal C=O group are ruled out based on energetics and kinetics arguments. Some of the previous photoionization mass spectrometric studies also reported 2 amu and 26 amu loss fragment ions, corresponding to hydrogen and acetylene loss. We could not identify such peaks in the mass spectrum of oleic acid.
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Affiliation(s)
- Maarten F Heringa
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland.,Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland
| | - Jay G Slowik
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland
| | - Maximilian Goldmann
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland
| | - Ruth Signorell
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland
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15
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Kostko O, Xu B, Jacobs MI, Ahmed M. Soft X-ray spectroscopy of nanoparticles by velocity map imaging. J Chem Phys 2017; 147:013931. [DOI: 10.1063/1.4982822] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- O. Kostko
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - B. Xu
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M. I. Jacobs
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - M. Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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16
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Antonsson E, Langer B, Halfpap I, Gottwald J, Rühl E. Photoelectron angular distribution from free SiO 2 nanoparticles as a probe of elastic electron scattering. J Chem Phys 2017; 146:244301. [PMID: 28668021 DOI: 10.1063/1.4986406] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In order to gain quantitative information on the surface composition of nanoparticles from X-ray photoelectron spectroscopy, a detailed understanding of photoelectron transport phenomena in these samples is needed. Theoretical results on the elastic and inelastic scattering have been reported, but a rigorous experimental verification is lacking. We report in this work on the photoelectron angular distribution from free SiO2 nanoparticles (d = 122 ± 9 nm) after ionization by soft X-rays above the Si 2p and O 1s absorption edges, which gives insight into the relative importance of elastic and inelastic scattering channels in the sample particles. The photoelectron angular anisotropy is found to be lower for photoemission from SiO2 nanoparticles than that expected from the theoretical values for the isolated Si and O atoms in the photoelectron kinetic energy range 20-380 eV. The reduced angular anisotropy is explained by elastic scattering of the outgoing photoelectrons from neighboring atoms, smearing out the atomic distribution. Photoelectron angular distributions yield detailed information on photoelectron elastic scattering processes allowing for a quantification of the number of elastic scattering events the photoelectrons have undergone prior to leaving the sample. The interpretation of the experimental photoelectron angular distributions is complemented by Monte Carlo simulations, which take inelastic and elastic photoelectron scattering into account using theoretical values for the scattering cross sections. The results of the simulations reproduce the experimental photoelectron angular distributions and provide further support for the assignment that elastic and inelastic electron scattering processes need to be considered.
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Affiliation(s)
- E Antonsson
- Physical Chemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
| | - B Langer
- Physical Chemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
| | - I Halfpap
- Physical Chemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
| | - J Gottwald
- Physical Chemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
| | - E Rühl
- Physical Chemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
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17
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Amanatidis S, Yoder BL, Signorell R. Low-energy photoelectron transmission through aerosol overlayers. J Chem Phys 2017; 146:224204. [PMID: 29166077 PMCID: PMC5469680 DOI: 10.1063/1.4983995] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 05/08/2017] [Indexed: 11/14/2022] Open
Abstract
The transmission of low-energy (<1.8 eV) photoelectrons through the shell of core-shell aerosol particles is studied for liquid squalane, squalene, and di-ethyl-hexyl-sebacate shells. The photoelectrons are exclusively formed in the core of the particles by two-photon ionization. The total photoelectron yield recorded as a function of shell thicknesses (1-80 nm) shows a bi-exponential attenuation. For all substances, the damping parameter for shell thicknesses below 15 nm lies around 8 to 9 nm and is tentatively assigned to the electron attenuation length at electron kinetic energies of ≲1 eV. The significantly larger damping parameters for thick shells (>20 nm) are presumably a consequence of distorted core-shell structures. A first comparison of aerosol and traditional thin film overlayer methods is provided.
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Affiliation(s)
- Stavros Amanatidis
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Bruce L Yoder
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Ruth Signorell
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
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18
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Nguyen-Truong HT. Electron inelastic mean free path at energies below 100 eV. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:215501. [PMID: 28437256 DOI: 10.1088/1361-648x/aa6b9d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Knowledge of electron inelastic mean free paths (IMFPs) is important for electron spectroscopy and microscopy studies. Here, we determine the IMFPs at energies below 100 eV for 10 elemental solids (V, Fe, Ni, Mo, Pd, Ag, Ta, W, Pt, and Au) within the dielectric formalism, using the energy-loss function calculated in the adiabatic local-density approximation of time-dependent density-functional theory. The resulting IMFPs at a few eV above the Fermi energy are comparable to those from ab initio calculations in the GW approximation of many-body theory. The present approach provides an alternative to evaluate hot-electron inelastic lifetimes.
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Affiliation(s)
- Hieu T Nguyen-Truong
- Theoretical Physics Research Group, Ton Duc Thang University, Ho Chi Minh City, Vietnam. Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
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19
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Luckhaus D, Yamamoto YI, Suzuki T, Signorell R. Genuine binding energy of the hydrated electron. SCIENCE ADVANCES 2017; 3:e1603224. [PMID: 28508051 PMCID: PMC5409453 DOI: 10.1126/sciadv.1603224] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/02/2017] [Indexed: 05/24/2023]
Abstract
The unknown influence of inelastic and elastic scattering of slow electrons in water has made it difficult to clarify the role of the solvated electron in radiation chemistry and biology. We combine accurate scattering simulations with experimental photoemission spectroscopy of the hydrated electron in a liquid water microjet, with the aim of resolving ambiguities regarding the influence of electron scattering on binding energy spectra, photoelectron angular distributions, and probing depths. The scattering parameters used in the simulations are retrieved from independent photoemission experiments of water droplets. For the ground-state hydrated electron, we report genuine values devoid of scattering contributions for the vertical binding energy and the anisotropy parameter of 3.7 ± 0.1 eV and 0.6 ± 0.2, respectively. Our probing depths suggest that even vacuum ultraviolet probing is not particularly surface-selective. Our work demonstrates the importance of quantitative scattering simulations for a detailed analysis of key properties of the hydrated electron.
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Affiliation(s)
- David Luckhaus
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Yo-ichi Yamamoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Toshinori Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Ruth Signorell
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
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20
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Hartweg S, Yoder BL, Garcia GA, Nahon L, Signorell R. Size-Resolved Photoelectron Anisotropy of Gas Phase Water Clusters and Predictions for Liquid Water. PHYSICAL REVIEW LETTERS 2017; 118:103402. [PMID: 28339280 DOI: 10.1103/physrevlett.118.103402] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Indexed: 05/05/2023]
Abstract
We report the first measurements of size-resolved photoelectron angular distributions for the valence orbitals of neutral water clusters with up to 20 molecules. A systematic decrease of the photoelectron anisotropy is found for clusters with up to 5-6 molecules, and most remarkably, convergence of the anisotropy for larger clusters. We suggest the latter to be the result of a local short-range scattering potential that is fully described by a unit of 5-6 molecules. The cluster data and a detailed electron scattering model are used to predict the anisotropy of slow photoelectrons in liquid water. Reasonable agreement with experimental liquid jet data is found.
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Affiliation(s)
- Sebastian Hartweg
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Bruce L Yoder
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Gustavo A Garcia
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP 48, 91192 Gif sur Yvette, France
| | - Laurent Nahon
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP 48, 91192 Gif sur Yvette, France
| | - Ruth Signorell
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
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21
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Lin PC, Wu ZH, Chen MS, Li YL, Chen WR, Huang TP, Lee YY, Wang CC. Interfacial Solvation and Surface pH of Phenol and Dihydroxybenzene Aqueous Nanoaerosols Unveiled by Aerosol VUV Photoelectron Spectroscopy. J Phys Chem B 2017; 121:1054-1067. [PMID: 28055205 DOI: 10.1021/acs.jpcb.6b10201] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although the significance of aqueous interfaces has been recognized in numerous important fields, it can be even more prominent for nanoscaled aqueous aerosols because of their large surface-to-volume ratios and prevalent existence in nature. Also, considering that organic species are often mixed with aqueous aerosols in nature, a fundamental understanding of the electronic and structural properties of organic species in aqueous nanoaerosols is essential to learn the interplay between water and organic solutes under the nanoscaled size regime. Here, we report for the first time the vacuum ultraviolet photoelectron spectroscopy of phenol and three dihydroxybenzene (DHB) isomers including catechol, resorcinol, and hydroquinone in the aqueous nanoaerosol form. By evaluating two photoelectron features of the lowest vertical ionization energies originated from the b1(π) and a2(π) orbitals for phenolic aqueous nanoaerosols, their interfacial solvation characteristics are unraveled. Phenolic species appear to reside primarily on/near the aqueous nanoaerosol interface, where they appear only partially hydrated on the aqueous interface with the hydrophilic hydroxyl group more solvated in water. An appreciable proportion of phenol is found to coexist with phenolate at/near the nanoaerosol interface even under a high bulk pH of 12.0, indicating that the nanoaerosol interface exhibits a composition distribution and pH drastically different from those of the bulk. The surface pH of phenol-containing aqueous nanoaerosols is found to be ∼2.2 ± 0.1 units more acidic than that of the bulk interior, as measured at the bulk pH of 12.0. From the photoelectron spectra of DHB aqueous nanoaerosols, the effects of numbers/arrangements of -OH groups are assessed. This study shows that the hydration extents, pH values, deprotonation status, and numbers/relative arrangements of -OH groups are crucial factors affecting the ionization energies of phenolic aqueous nanoaerosols and thus their redox-based activities. The multifaceted implications of the present study in the aerosol science, atmospheric/marine chemistry, and biological science are also addressed.
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Affiliation(s)
| | | | | | | | | | - Tzu-Ping Huang
- National Synchrotron Radiation Research Center , Hsinchu, Taiwan 30076, ROC
| | - Yin-Yu Lee
- National Synchrotron Radiation Research Center , Hsinchu, Taiwan 30076, ROC
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22
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Jacobs MI, Kostko O, Ahmed M, Wilson KR. Low energy electron attenuation lengths in core–shell nanoparticles. Phys Chem Chem Phys 2017; 19:13372-13378. [DOI: 10.1039/c7cp00663b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A velocity map imaging spectrometer is used to measure photoemission from free core–shell nanoparticles, where a salt core is coated with a liquid hydrocarbon shell (i.e. squalane).
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Affiliation(s)
- Michael I. Jacobs
- Department of Chemistry
- University of California
- Berkeley
- USA
- Chemical Sciences Division
| | - Oleg Kostko
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
| | - Musahid Ahmed
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
| | - Kevin R. Wilson
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
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23
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Jacobs MI, Xu B, Kostko O, Heine N, Ahmed M, Wilson KR. Probing the Heterogeneous Ozonolysis of Squalene Nanoparticles by Photoemission. J Phys Chem A 2016; 120:8645-8656. [DOI: 10.1021/acs.jpca.6b09061] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael I. Jacobs
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Bo Xu
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Oleg Kostko
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Nadja Heine
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Kevin R. Wilson
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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24
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Chang PC, Yu Y, Wu ZH, Lin PC, Chen WR, Su CC, Chen MS, Li YL, Huang TP, Lee YY, Wang CC. Molecular Basis of the Antioxidant Capability of Glutathione Unraveled via Aerosol VUV Photoelectron Spectroscopy. J Phys Chem B 2016; 120:10181-10191. [DOI: 10.1021/acs.jpcb.6b04631] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | - Tzu-Ping Huang
- National Synchrotron Radiation Research Center, Hsinchu, Taiwan 30076, ROC
| | - Yin-Yu Lee
- National Synchrotron Radiation Research Center, Hsinchu, Taiwan 30076, ROC
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25
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Nanofocusing, shadowing, and electron mean free path in the photoemission from aerosol droplets. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.05.046] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Cremer JW, Thaler KM, Haisch C, Signorell R. Photoacoustics of single laser-trapped nanodroplets for the direct observation of nanofocusing in aerosol photokinetics. Nat Commun 2016; 7:10941. [PMID: 26979973 PMCID: PMC4799369 DOI: 10.1038/ncomms10941] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/03/2016] [Indexed: 11/23/2022] Open
Abstract
Photochemistry taking place in atmospheric aerosol droplets has a significant impact on the Earth's climate. Nanofocusing of electromagnetic radiation inside aerosols plays a crucial role in their absorption behaviour, since the radiation flux inside the droplet strongly affects the activation rate of photochemically active species. However, size-dependent nanofocusing effects in the photokinetics of small aerosols have escaped direct observation due to the inability to measure absorption signatures from single droplets. Here we show that photoacoustic measurements on optically trapped single nanodroplets provide a direct, broadly applicable method to measure absorption with attolitre sensitivity. We demonstrate for a model aerosol that the photolysis is accelerated by an order of magnitude in the sub-micron to micron size range, compared with larger droplets. The versatility of our technique promises broad applicability to absorption studies of aerosol particles, such as atmospheric aerosols where quantitative photokinetic data are critical for climate predictions.
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Affiliation(s)
- Johannes W. Cremer
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland
| | - Klemens M. Thaler
- Laboratory for Applied Laser Spectroscopy, Chair of Analytical Chemistry, Technical University of Munich, Marchioninistrasse 17, D-81377 Munich, Germany
| | - Christoph Haisch
- Laboratory for Applied Laser Spectroscopy, Chair of Analytical Chemistry, Technical University of Munich, Marchioninistrasse 17, D-81377 Munich, Germany
| | - Ruth Signorell
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland
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27
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Ellis JL, Hickstein DD, Xiong W, Dollar F, Palm BB, Keister KE, Dorney KM, Ding C, Fan T, Wilker MB, Schnitzenbaumer KJ, Dukovic G, Jimenez JL, Kapteyn HC, Murnane MM. Materials Properties and Solvated Electron Dynamics of Isolated Nanoparticles and Nanodroplets Probed with Ultrafast Extreme Ultraviolet Beams. J Phys Chem Lett 2016; 7:609-615. [PMID: 26807653 DOI: 10.1021/acs.jpclett.5b02772] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present ultrafast photoemission measurements of isolated nanoparticles in vacuum using extreme ultraviolet (EUV) light produced through high harmonic generation. Surface-selective static EUV photoemission measurements were performed on nanoparticles with a wide array of compositions, ranging from ionic crystals to nanodroplets of organic material. We find that the total photoelectron yield varies greatly with nanoparticle composition and provides insight into material properties such as the electron mean free path and effective mass. Additionally, we conduct time-resolved photoelectron yield measurements of isolated oleylamine nanodroplets, observing that EUV photons can create solvated electrons in liquid nanodroplets. Using photoemission from a time-delayed 790 nm pulse, we observe that a solvated electron is produced in an excited state and subsequently relaxes to its ground state with a lifetime of 151 ± 31 fs. This work demonstrates that femotosecond EUV photoemission is a versatile surface-sensitive probe of the properties and ultrafast dynamics of isolated nanoparticles.
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Affiliation(s)
- Jennifer L Ellis
- JILA-NIST and Department of Physics, University of Colorado , 440 UCB, Boulder, Colorado 80309, United States
| | - Daniel D Hickstein
- JILA-NIST and Department of Physics, University of Colorado , 440 UCB, Boulder, Colorado 80309, United States
| | - Wei Xiong
- JILA-NIST and Department of Physics, University of Colorado , 440 UCB, Boulder, Colorado 80309, United States
- Department of Chemistry and Biochemistry, University of California San Diego , La Jolla, California 92093, United States
| | - Franklin Dollar
- JILA-NIST and Department of Physics, University of Colorado , 440 UCB, Boulder, Colorado 80309, United States
| | - Brett B Palm
- CIRES and Department of Chemistry and Biochemistry, University of Colorado , Boulder, Colorado 80309, United States
| | - K Ellen Keister
- JILA-NIST and Department of Physics, University of Colorado , 440 UCB, Boulder, Colorado 80309, United States
| | - Kevin M Dorney
- JILA-NIST and Department of Physics, University of Colorado , 440 UCB, Boulder, Colorado 80309, United States
| | - Chengyuan Ding
- JILA-NIST and Department of Physics, University of Colorado , 440 UCB, Boulder, Colorado 80309, United States
| | - Tingting Fan
- JILA-NIST and Department of Physics, University of Colorado , 440 UCB, Boulder, Colorado 80309, United States
| | - Molly B Wilker
- Department of Chemistry and Biochemistry, University of Colorado , Boulder, Colorado 80309, United States
| | - Kyle J Schnitzenbaumer
- Department of Chemistry and Biochemistry, University of Colorado , Boulder, Colorado 80309, United States
| | - Gordana Dukovic
- Department of Chemistry and Biochemistry, University of Colorado , Boulder, Colorado 80309, United States
| | - Jose L Jimenez
- CIRES and Department of Chemistry and Biochemistry, University of Colorado , Boulder, Colorado 80309, United States
| | - Henry C Kapteyn
- JILA-NIST and Department of Physics, University of Colorado , 440 UCB, Boulder, Colorado 80309, United States
| | - Margaret M Murnane
- JILA-NIST and Department of Physics, University of Colorado , 440 UCB, Boulder, Colorado 80309, United States
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28
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David G, Esat K, Ritsch I, Signorell R. Ultraviolet broadband light scattering for optically-trapped submicron-sized aerosol particles. Phys Chem Chem Phys 2016; 18:5477-85. [DOI: 10.1039/c5cp06940h] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A broadband light scattering experiment for the characterization of size and refractive index of single submicron-to-micron sized aerosol particles is presented.
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Affiliation(s)
- Grégory David
- Laboratory of Physical Chemistry
- ETH Zurich
- Zurich
- Switzerland
| | - Kıvanç Esat
- Laboratory of Physical Chemistry
- ETH Zurich
- Zurich
- Switzerland
| | - Irina Ritsch
- Laboratory of Physical Chemistry
- ETH Zurich
- Zurich
- Switzerland
| | - Ruth Signorell
- Laboratory of Physical Chemistry
- ETH Zurich
- Zurich
- Switzerland
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