Öffnet in neuem Fenster Opens in a new window Öffnet externe Seite Opens an external site Öffnet externe Seite in neuem Fenster Opens an external site in a new window

Department Atomic-Scale Dynamics in Light-Energy Conversion

News

Water adsorption in mesoporous carbon materials - enlarged view

Schematic representation of water adsorption in mesoporous carbon materials according to our findings as a function of humidity and nitrogen content in the carbon materials. © Adv. Funct. Mater. 2024, 2406528

June 2024 – Our paper about water confinement in nitrogen-rich nanoporous carbon materials has been published in the journal of Advanced Functional Materials.

In a joint collaboration with colleagues from the Max Planck Institute for Chemistry in Mainz, the Friedrich Schiller University Jena and HZB, we investigated the interaction between water molecules and surfaces in porous carbon-based materials. By using in situ scanning transmission X-ray microscopy, resonant inelastic X-ray scattering and near-ambient pressure resonant photoelectron spectroscopy, we found that the water adsorption on nitrogen-containing nanoporous carbon surfaces is controlled by a subtle balance between water–water and water–surface hydrogen bonding interactions, which together determine the water structures formed and their stability. Please click here for more information.


New group members - enlarged view

A warm welcome to our newest group members: Dr. Rico Mayro Tanyag, Hubert Czternastek, and Moritz Meißner. © Aswin Jyothilakshmi Ravi / Robert Seidel

June 2024 – New group members

We welcome three new members to our group. Postdoc Dr. Rico Mayro Tanyag will support the upgrade of our SOL³PES setup and, after completion, will study transition metal-oxide nanoparticle-water interfaces using resonant photoelectron spectroscopy. PhD student Hubert Czternastek will investigate plasmonic catalysts in-situ using pump-probe spectroscopy and Master student Moritz Meißner will develop pump-probe diffuse anomalous fine-structure instruments at BESSY II, to investigate the photoinduced magnetic phase transition in iron-rhodium.


Group outing May 2024 - enlarged view

PS-ADLU spent the annual group outing at the forest climbing park in Jungfernheide. © Robert Seidel, Aswin Jyothilakshmi / HZB

May 2024 – Group outing to the forest climbing park Jungfernheide

This year our annual group outing took us to one of Berlin’s largest high ropes courses located in Charlottenburg. For many of us it was the first time that we climbed, hung, slid and crawled between trees several meters high. There were different routes with different levels of difficulty (marked by a color code from green-easy to blue, red, to black-very difficult). Nick, Luise, and Moritz successfully mastered the black route, while the rest of us had fun on the easier courses. After three hours we were all totally exhausted and will certainly have sore muscles for the next few days. Afterwards we regained some strength in a nearby beer garden and played a round of Mölkky – many thanks to Thomas for introducing us to this very fascinating game.


ERC Project WATER-X - enlarged view

Robert aims to investigate promising transition metal oxide nanoparticles relevant to photocatalytic water splitting. The project WATER-X is funded by the EU (project number 101126299). © Robert Seidel / HZB

March 2024 – ERC Consolidator Grant for Robert

Congratulations! For his project WATER-X, Robert was awarded an ERC Consolidator Grant of 2 million euros. Over the next five years, he will intensify his research on promising transition metal oxide nanoparticles relevant to photocatalytic water splitting reactions. Using static and time-resolved soft X-ray resonant photoelectron spectroscopy, Robert aims to measure the short-lived molecular intermediates and their associated electronic structure, their lifetimes, energetics, photoelectron angular distributions, and their decay mechanisms. To this end, he will hire two postdocs and three PhD students who will work at the BESSY II synchrotron in Adlershof and in Iain Wilkinson’s newly commissioned laser laboratory on the Wannsee campus. For more information see here.


February 2023 – Renske is appointed as S-W2-Professor at TU Berlin!

Congratulations! Renske is now officially affiliated with the Institute of Optics and Atomic Physics at the Technical University Berlin. Check out the news!


Paper published in Nature Reviews Chemistry

Started during the pandemic, we finally finished our review paper on time-resolved transmission electron microscopy. What a tour de force! Check it out here in Nature Reviews Chemistry!


Sodium intercalation in NiFeOx - enlarged view

Our TOC figure in the JPC Letters. ©J. Phys. Chem. Lett. 2023, 14, 545−551

January 2023 - Hanna’s first first-author paper!

Congratulations Hanna! Our paper about the reversible and irreversible cation intercalation in NiFeOx oxygen evolution catalysts in alkaline media was published in The Journal of Physical Chemistry Letters. Together with our colleagues from the Leiden Institute of Chemistry at the Leiden university, The Netherlands, and from HZB, we studied the intercalation process by measuring the soft X-ray absorption spectra at the nickel L-edge as well as at the sodium and oxygen K-edges of this layered Ni0.8Fe0.2Ox electrocatalyst during the oxygen evolution reaction using NaOH as electrolyte. The spectra reveal a (reversible) increase in the sodium intensity at the intercalation potential, which also coincides with an increase in the nickel oxidation state. However, the reversible increase in intercalated Na+ ions did not lead to an increase in the water content of the catalyst layer, which suggests that the intercalation of Na+ has little effect on the catalyst morphology. Our work also supports previous electrochemical studies that Na ions from the electrolyte are being intercalated into the γ-phase of Ni-based electrocatalysts for water oxidation. For more information about this fascinating story, please click here.


Dip-and-pull technique - enlarged view

A) Sketch and b) photograph of the dip-and-pull setup with the yellow iron hexacyanide solution in a beaker sitting in the vacuum chamber under ambient pressure conditions. The three electrodes are first c) dipped into the electrolyte solution and then d) pulled up, with measurements taken while slowly moving between positions d) and e). The liquid meniscus is clearly shown in the photograph of f). The dashed circle in b) highlights some small hydrogen bubbles at the counter electrode. © J. Chem. Phys. 157, 244701 (2022)

December 2022 - Our spectroelectrochemistry paper about operando measurements on iron hexacyanide using the dip-and-pull technique has been published in the Journal of Chemical Physics

What a nice Christmas present! Our ‘multi-synchrotron’ work between MAXIV, Lund, and BESSY II, Berlin, on X-ray photoelectron spectroscopy of the redox reaction of iron hexacyanide has been published in JCP as part of the Special Topic on ‘In situ and Operando characterization’. While our colleagues around Robert Temperton from the HiPPIE beamline at MAXIV performed ambient-pressure XPS measurements using the so-called dip-and-pull technique to study the conversion of [FeIII(CN)6]3− in water into [FeII(CN)6]4−  and following the (reversible) iron 2p signal, Robert and Wilson at HZB measured the reference iron 2p spectra with the liquid-jet technique for both redox states with the SOL³PES setup at BESSY II. The dip-and-pull technique is a fairly new technique in which a thin liquid film is prepared by pulling an electrode out of a degassed solution beaker in a ‘vacuum’ chamber equilibrated by the vapor pressure of the electrolyte solution (in case of water, ~10 mbar at 10°C). Our study demonstrates that the liquid film on the electrode is electrochemically active such that the relative potential difference between the working electrode and the solution can be controlled to a large extent. For more information about this technically demanding experiment, please click here.


Iain_Wilkinson, Robert_Seidel, LIDUX - enlarged view

Iain shows Robert the newest installations in the temperature and humidity-controlled level-5 clean room in the LIDUX lab. © Robert Seidel / HZB

November 2022 – Visiting LIDUX Laser Lab

Robert has visited Iain Wilkinson in his new state-of-the-art ‘Liquid and Interfacial Dynamics with Ultrafast X-rays facility’, LIDUX, at the Wannsee campus of HZB. Liquid jet and flatjet experiments with this impressive, powerful 500 W laser system will be available by the end of 2023. It will then be possible to observe ultra-short femtosecond processes after UV/Vis excitation by probing them with few-femtosecond soft X-ray pulses, capable of kicking out electrons from deeper lying core-orbitals that offer much cleaner spectral fingerprints compared to electrons ejected from the valence band. This laser offers the excellent time resolution of an X-ray free-electron laser, but does not generate any unwanted space charges in the samples due to lower pulse intensity and a much higher repetition rate of 53 kHz. Check out more here.


Garlef Wartner PhD Defense - enlarged view

Top: Robert, Garlef and Dennis smile before the PhD defense. Middle: The smiling continues when Garlef received his doctorate hat from Dennis. Bottom: Garlef and Jan Lüning explore the richly decorated hat and its stories. ©Robert Seidel / HZB

Garlef Wartner is now Dr. Garlef Wartner!

Congratulations Garlef! With many, many spectroscopy-related questions from the PhD committee, consisting of the reviewers Simone Raoux (HZB/Humboldt University), Olle Björneholm (Uppsala University), and Robert, as well as the Humboldt University professors Oliver Benson, Emil List-Kratochvil, and Jan Lüning, Garlef delivered a brilliant performance in his defense. Overall, his PhD was graded with magna cum laude. Garlef will continue his work on electrochemical water splitting-cells in the group of Marc Tesch from the Max Planck Institute for Chemical Energy Conversion in Mülheim an der Ruhr, but will stay in Adlershof and work in collaboration with the Fritz Haber Institute Berlin and HZB. So, it is not time to say goodbye yet.


PS-ADLU_Excursion_2022 - enlarged view

PS-ADLU is on the hunt! First, we strengthen ourselves at an Indian restaurant (upper left). There was some time for mulled wine between the individual quests (upper right). Everyone was happy after the successful hunt (lower left). The various stations to which our scavenger hunt led us (lower right).

November 2022 - We spent our annual excursion on a scavenger hunt through downtown Berlin

After a rich Indian meal in the Amrit restaurant on Oranienburger Straße, we started a scavenger hunt through Berlin, where we had to solve many puzzles and quests. Because we solved them so efficiently, we had plenty of time between the quests for some mulled wine at the Christmas market on Bebelplatz. It was a wonderful afternoon!


Beamtime at HiPPIE MAXIV - enlarged view

Top: Robert is fixing a leaking connector on the liquid microjet injector. Bottom: The most important people of the beamtime: Francis, Robert, Robert, Lewis, and Kevin. ©Robert Seidel / HZB

November 2022 Beamtime at MAXIV

Robert joined Kevin Lovelock and his team from Reading University for a four-day beamtime at MAXIV in Lund, Sweden. We studied the resonant Auger spectra of zinc salts in different solvents and were particularly interested in the participator Auger fingerprints of the anions and looked for trends in the (valence) binding energies upon changing the solvent. This work began in an earlier beamtime by Kevin Lovelock at BESSY II with the SOL³PES and is now being continued at the HiPPIE endstation at MAXIV, which is managed by Robert Temperton. After careful data analysis by the PhD students Lewis and Francis, the data from both synchrotron beamtimes will (hopefully) find their way into a publication.


Nanodiamonds - enlarged view

Two different nanodiamond materials were investigated: C230H106 (left) and C286H68 (right). The grey and brown colored spheres represent hydrogen and fullerene-like carbon-atoms. Both species are needed for electron emission upon excitation with visible blue light. © T Kirschbaum / HZB

Christoph's paper on solvated electrons from nanodiamonds is published in Nanoscale!

Congrats, Christoph! Together with collaborators from Paris-Saclay, France, Uppsala University, Sweden, University of Stuttgart, Free University Berlin and Julius-Maximilians-University Würzburg as well as with colleagues from HZB, Franziska Buchner, Thorren Kirschbaum, Annika Bande and Tristan Petit, they were able to show for the first time spectroscopically the emission of solvated electrons from nanodiamonds with hydrogen and fullerene-like carbon on the surface upon excitation with visible blue light. Without these species at the surface, deep UV-light is needed and no electron emission upon visible light excitation was detected. This result is a big step forward and will put nanodiamonds with hydrogen/fullerene surface ‘treatment’ in the spotlight as potential candidates for photocatalysts used for CO2-reduction or nitrogen-to-ammonia conversion. Check out the paper here as well as the HZB press release here.


Hanna spoils us during group meeting!

What a treat! Hanna made vegan, vegetarian, and carnivore bread sticks. Yum!


Article published in Angewandte Chemie!

Our article on Ni-based photoredox catalysis was published in Angew. Chem. ! This work resulted from a collaboration with the groups of Arne Thomas, Bart Pieber, Henrike Müller-Werkmeister, and Josh Vura-Weis. Check it out.


Renske and Thomas, Lemont, APS beamtime - enlarged view

Hungry, but happy: (from left to right) Jack, Laura, Rachel, Thomas, Renske, Conner and Tyler are waiting for the Mexican food in a restaurant in Lemont, Illinois. © Renske van der Veen / HZB

September 2022 - Beamtime at the APS

Renske and Thomas joined Rachel’s and Jack’s beamtime at the Advanced Photon Source at Argonne National Laboratory just south of Chicago. It was an exhausting but successful six-days/24-hours transient-hard-X-ray-absorption-measurement marathon of bimetallic molecular complexes relevant for photocatalysis.


ICD in liquid ammonia - enlarged view

After careful subtraction of the gas-phase ammonia spectrum, we were able to identify a broad shoulder in the nitrogen 1s Auger spectrum that can be assigned to ICD and shake-up satellite states. © Structural Dynamics 9, 044901 (2022)

August 2022 - Our article about intermolecular Coulombic decay in liquid ammonia has been published in Structural Dynamics.

Our colleagues from FHI (Winter group) and from Prague (Slavíček group and Hanns Christian Schewe from Jungwirth group) together with Robert measured Auger spectra of liquid ammonia for the first time. The intermolecular Coulombic decay (ICD) fingerprints are hidden under a shoulder on the high-energy side of the normal nitrogen Auger peak overlaid by shake-up satellites. In ICD, an initially core or inner-valence ionized atom or molecule electronically decays, and the released energy ionizes a neighboring entity via Coulombic electron interactions. Thanks to the theorists from Prague, we were able to deconvolute the messy Auger-peak structure, and our calculations support that ICD does indeed contribute. Liquid ammonia is a hydrogen-bonded system, and the electronic processes can couple to nuclear dynamics following core-level ionization. Unlike in liquid water, we found no significant proton-transfer dynamics occurring between the hydrogen-bonded units within the respective N 1s core-hole lifetime. You can read more about this fascinating basic-research study here.


Aswin Jyothilakshmi Ravi - enlarged view

Aswin on his first tour through the BESSY II synchrotron. © Hanna Trzesniowski / HZB

August 2022 - Welcome Aswin!

Phd candidate Aswin Jyothilakshmi Ravi (in short JR) from Kozhikode, India, joined PS-ADLU. A very warm welcome!


Robert Seidel GRC Holderness 2022 - enlarged view

Robert next to his poster at the GRC in Holderness, New Hampshire. © Robert Seidel / HZB

July 2022 - Gordon Research Conference in Holderness

After a three-year hiatus due to the Corona pandemic, Robert attended the Gordon Research Conference of Water and Aqueous Solutions in Holderness, New Hampshire, USA. He presented recent liquid microjet data from sulfuric acid in water. From the valence and core-level spectra we can derive the dissociation constant as a function of probing depth, temperature and concentration. These dissociation constants are important input parameters for various climate (change) models, since aqueous aerosols of sulfate and bisulfate ions play a crucial role in cloud formation.


July 2022 - Our department becomes part of the UniSysCat cluster

UniSysCat stands for Unifying Systems in Catalysis, which is a Cluster of Excellence.  More than 260 researchers from four universities and four research institutes in the Berlin and Potsdam area work together on current challenges in the highly relevant field of catalysis.

We are looking forward to many fruitful collaborations!

UniSysCat

July 2022 - Thomas attends the Ultrafast Phenomena conference

Together with Jack and Rachel from UIUC he enjoyed many good talks & French croissants...

enlarged view

Thomas, Jack & Rachel enjoying themselves in Montreal


HZB retreat 2022 - enlarged view

The weather changed dramatically during the two-day retreat. ©Robert Seidel / HZB

June 2022 - HZB retreat in Schmöckwitz

Our annual 2-day retreat for all group leaders at the HZB took place in beautiful Schmöckwitz, located at the very east of Berlin on the border to Brandenburg. A tightly packed schedule with talks, presentations and group discussions on the strategies and future plans of BESSY II and III awaited Renske and Robert.


Martin Gruebele at BESSY II - enlarged view

Martin Gruebele and Renske van der Veen on big tour through BESSY II: control room (upper left), experimental hall (upper right), in the BESSY tunnel (lower left), at the SOL³PES station (lower right). © Robert Seidel / HZB

June 2022 - Martin Gruebele from the University of Illinois at Urbana-Champaign visited us.

Martin is a former colleague of Renske in the Department of Chemistry at the University of Illinois at Urbana-Champaign. Renske and Robert gave Martin a detailed tour through the BESSY synchrotron tunnel and the storage ring. Thanks to the ongoing shutdown we could show him all sacred places at BESSY II.


March/April 2022 - Jack, Rachel & Conner visit BESSY II

PhD students Jack, Rachel, and Conner from UIUC flew all the way from Illinois to Berlin for three weeks of beam time at the UE52_SGM beam line at BESSY.


May 2022 - PS-ADLU grows!

Robert Seidel and his group joined Renske van der Veen’s Department of Atomic-Scale Dynamics in Light-Energy Conversion (PS-ADLU). A warm welcome everyone!