Physical Chemistry Department -

Three Accepted papers…

In possible proof that good things do indeed come in threes:

  1. Lu’s long awaited paper  Water Dissociative Adsorption on α-Al2O3(1120) is Controlled by Surface Site Undercoordination, Density and Topology was recently accepted for publication in Journal of Physical Chemistry C. If you’ve ever wanted to understand how small amounts of water interact with α-Al2O3 single crystal surfaces (and you should, it’s really interesting) this paper and our previous 3 efforts on this subject make for nice reading.
  2. A collaborative paper with Mohsen Sajadi, Tobias Kampfrath and Martin Wolf, on the so-called THz Kerr Effect in methanol and how it can help you assign the dielectric response, The Nature of the Dielectric Response of Methanol Revealed by the Terahertz Kerr Effect, was accepted for publication in Journal of Physical Chemistry Letters.
  3. Yujin’s paper on using VSF spectroscopy to quantify the polarizability of the perchlorate anion at the air/water interface, Experimentally Quantifying Anion Polarizability at the Air/Water Interface, was accepted for publication in Nature Communications.

We’re looking for people at the MS, PhD and Post-Doctoral levels

We are currently looking for multiple people at the MS, PhD and Post Doctoral levels to fill open positions related to understanding electron transfer across solid/liquid water interfaces and building the ultimate in surface-specific vibrational spectroscopy. If you care about aqueous photo-electrochemistry (and you should), if you care about building better tools to probe molecular structure and reactivity at buried interfaces (and you should) this is an exciting time. For more details see the flyer: Open Positions

Support for our (photo)electrochemical activities…

In a thoughtful attempt of the European Commission to combat the dismal Berlin fall weather November 28th brought the news that Kramer’s ERC Consolidator grant proposal —  SOLWET: Electron Transfer Across Solid/Liquid Interfaces: Elucidating Elementary Processes from Femtoseconds to Seconds — was “retained for funding”. The generous support this includes will allow the dramatic expansion of our activities studying ultrafast (photo)electrochemistry. Stay tuned for more about what project encompasses and photos from a suitable celebratory activity (as soon as we decide what that might actually be 🙂 ).

On anion polarizability at the air/water interface (a preprint)…

Much work by many clever folks over the last 25 years has shown that, contra expectations from classical theories of solutions, some — mostly larger, polarizable — anions adsorb on the air/water interface. While this phenomena has been extensively studied both theoretically and experimentally, understanding the contribution of anion polarizability to the free energy of adsorption has proven surprisingly challenging: anion polarization cannot rationalize known trends in anion adsorption some simulation approaches and interface active anions appear not to be polarized in others. One possible explanation for this state of the affairs is that, in the absence of experimental constraints on interfacial anion polarizability to parameterize classical descriptions or validate interfacial anion polarization calculated from ab-initio simulations, theoretical description of interfacial polarizability is beset by systematic error.

Yujin has just submitted a paper showing that the symmetry of the polarizability tensor of perchlorate, a known interface-active anion, changes by more than 2x in moving from bulk liquid to the air/water interface and that this change is concentration dependent: as the interfacial population of perchlorate increases the polarizability tensor grows still more anisotropic. This work is the first experimental observation of an anion’s interfacial polarizability and the effect that it describes not explicitly parameterized or shown to occur in any theoretical approach. It thus seems likely that reproducing it in simulation is a useful step in trying to resolve the role of polarizability in anion adsorption at the air/water interface (for the preprint see the arXiv).

Comings (or at least goings)

After a highly successful summer stint in Berlin Nick Pant has returned to McGill. By dint of dogged determination and a knack for finding some (superficially unrelated) prior work he managed to help us get control of the electrodeposition of various FeOx films on several substrates. We (and particularly Julius) are very grateful.

Should electrochemists care about VSF spectroscopy?

Short answer, yes. If you’re still not convinced see Yujin’s invited reference module, In-Situ Probing of Adsorbates at Electrochemical Interfaces with Vibrational Sum Frequency Spectroscopy, just accepted for publication in the Enclyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry ( e-mail for preprint).

What does surface potential do to self-assembled monolayers of photoswitchable molecules?

Tobias and Yujin’s paper trying to answer this question for a SAM formed of spiropyrans has been accepted for publication in Journal of Physics: Condensed Matter. In it they show that if you’d like to build an electrochemical sensor using an electrode covered with a photoswitchable SAM (and, well, of course you’d like to) you need to quantitatively account for the influence of the surface potential on the composition of the photostationary states. For those who need more, the abstract:

Surfaces whose macroscopic properties can be switched by light are potentially useful in a wide variety of applications. One such promising application is electrochemical sensors that can be gated by optically switching the electrode on or o ff. One way to make such a switchable electrode is by depositing a self-assembled monolayer of bistable, optically switchable molecules onto an electrode surface. Quantitative application of any such sensor requires understanding how changes in interfacial field aff ect the composition of photostationary states, i.e. how does electrode potential a ect the extent to which the electrode is on or o ff when irradiated, and the structure of the SAM. Here we address these questions for a SAM of a 6-nitro-substituted spiro[2H- 1-benzopyran-2,2′-indoline] covalently attached through a dithiolane linker to an Au electrode immersed in a 0.1 M solution of Tetramethylammonium hexauorophosphate in Acetonitrile using interface-speci c vibrational spectroscopy. We find that in the absence of irradiation, when the SAM is dominated by the closed spiropyran form, variations in potential of 1 V have little eff ect on spiropyran relative stability. In contrast, under UV irradiation small changes in potential can have dramatic e ects: changes in potential of 0.2 V can completely destabilize the open, merocyanine form of the SAM relative to the spiropyran and dramatically change the chromophore orientation. Quantitatively accounting for these e ects is necessary to employ this, or any other optically switchable bistable chromophore, in electrochemical applications.


In an attempt to further evangelize our efforts in femtosecond time resolved electrochemistry, Kramer gave an invited talk at the Ninth International Conference on Advanced Vibrational Spectroscopy (ICAVS9) in Victoria, Canada titled Towards Experimentally Probing the Hydrogen Evolution Reaction on Pt and Au with Femtosecond Time Resolution.

A Summer Visitor

Nick Pant (undergraduate student from McGill University) has arrived to do a summer internship with us (under Julius’ wing) to work on electrochemical characterization of Fe-oxides. His stay is supported through the DAAD Rise Germany program.

Because there are some people who don’t go to the spring DPG meeting…

In a continued attempt to tell as many people as possible about our ongoing activities Yujin went on a China tour giving talks at the Harbin Institute of Technology to chemical engineers on May 15th (Application of Vibrational Sum Frequency Spectroscopy to Study Various Surfaces and Interfaces) and at the State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen University, on May 18th (Probing Electrochemical Interfaces with Vibrational Sum Frequency Spectroscopy). In pursuit of the same goal Kramer went to Kaiserslautern, because it’s closer,  for this year’s Bunsentagung where he gave a talk on May 26th titled Towards a Femtosecond Resolved View of the Mechanism of the Hydrogen Evolution Reaction on Au.