@article{KarakStepanenkoAddicoatetal.2022,
  author    = {Karak, Suvendu and Stepanenko, Vladimir and Addicoat, Matthew A. and Keßler, Philipp and Moser, Simon and Beuerle, Florian and W{\"u}rthner, Frank},
  title     = {A Covalent Organic Framework for Cooperative Water Oxidation},
  series = {Journal of the American Chemical Society},
  volume    = {144},
  journal   = {Journal of the American Chemical Society},
  number    = {38},
  issn      = {0002-7863},
  doi       = {10.1021/jacs.2c07282},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287591},
  pages     = {17661-17670},
  year      = {2022},
  abstract  = {The future of water-derived hydrogen as the "sustainable energy source" straightaway bets on the success of the sluggish oxygen-generating half-reaction. The endeavor to emulate the natural photosystem II for efficient water oxidation has been extended across the spectrum of organic and inorganic combinations. However, the achievement has so far been restricted to homogeneous catalysts rather than their pristine heterogeneous forms. The poor structural understanding and control over the mechanistic pathway often impede the overall development. Herein, we have synthesized a highly crystalline covalent organic framework (COF) for chemical and photochemical water oxidation. The interpenetrated structure assures the catalyst stability, as the catalyst's performance remains unaltered after several cycles. This COF exhibits the highest ever accomplished catalytic activity for such an organometallic crystalline solid-state material where the rate of oxygen evolution is as high as ∼26,000 μmol L\(^{-1}\) s\(^{-1}\) (second-order rate constant k ≈ 1650 μmol L s\(^{-1}\) g\(^{-2}\)). The catalyst also proves its exceptional activity (k ≈ 1600 μmol L s\(^{-1}\) g\(^{-2}\)) during light-driven water oxidation under very dilute conditions. The cooperative interaction between metal centers in the crystalline network offers 20-30-fold superior activity during chemical as well as photocatalytic water oxidation as compared to its amorphous polymeric counterpart.},
  language  = {en}
}
@article{KernHaagsEggeretal.2023,
  author    = {Kern, Christian S. and Haags, Anja and Egger, Larissa and Yang, Xiaosheng and Kirschner, Hans and Wolff, Susanne and Seyller, Thomas and Gottwald, Alexander and Richter, Mathias and de Giovannini, Umberto and Rubio, Angel and Ramsey, Michael G. and Bocquet, Fran{\c{c}}ois C. and Soubatch, Serguei and Tautz, F. Stefan and Puschnig, Peter and Moser, Simon},
  title     = {Simple extension of the plane-wave final state in photoemission: bringing understanding to the photon-energy dependence of two-dimensional materials},
  series = {Physical Review Research},
  volume    = {5},
  journal   = {Physical Review Research},
  number    = {3},
  doi       = {10.1103/PhysRevResearch.5.033075},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350330},
  year      = {2023},
  abstract  = {Angle-resolved photoemission spectroscopy (ARPES) is a method that measures orbital and band structure contrast through the momentum distribution of photoelectrons. Its simplest interpretation is obtained in the plane-wave approximation, according to which photoelectrons propagate freely to the detector. The photoelectron momentum distribution is then essentially given by the Fourier transform of the real-space orbital. While the plane-wave approximation is remarkably successful in describing the momentum distributions of aromatic compounds, it generally fails to capture kinetic-energy-dependent final-state interference and dichroism effects. Focusing our present study on quasi-freestanding monolayer graphene as the archetypical two-dimensional (2D) material, we observe an exemplary E\(_{kin}\)-dependent modulation of, and a redistribution of spectral weight within, its characteristic horseshoe signature around the \(\bar {K}\) and \(\bar {K´}\) points: both effects indeed cannot be rationalized by the plane-wave final state. Our data are, however, in remarkable agreement with ab initio time-dependent density functional simulations of a freestanding graphene layer and can be explained by a simple extension of the plane-wave final state, permitting the two dipole-allowed partial waves emitted from the C 2p\(_z\) orbitals to scatter in the potential of their immediate surroundings. Exploiting the absolute photon flux calibration of the Metrology Light Source, this scattered-wave approximation allows us to extract E\(_{kin}\)-dependent amplitudes and phases of both partial waves directly from photoemission data. The scattered-wave approximation thus represents a powerful yet intuitive refinement of the plane-wave final state in photoemission of 2D materials and beyond.},
  language  = {en}
}