* Corresponding authors

^a Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
E-mail: lothar.weinhardt@kit.edu

^b Department of Chemistry and Biochemistry, University of Nevada, Las Vegas (UNLV), NV 89154-4003, USA

^c Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 18/20, 76128 Karlsruhe, Germany

^d ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany

^e Department of Physics, Stockholm University, AlbaNova University Centre, 10691 Stockholm, Sweden

^f Institute of Chemistry, University of Zurich, Winterthurerstr. 190, CH-8057 Zurich, Switzerland

^g Universität Würzburg, Experimentelle Physik VII, Am Hubland, 97074 Würzburg, Germany

^h Renewable Energy, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany

ⁱ Institut für Physik und Chemie, Brandenburgische Technische Universität Cottbus-Senftenberg, Platz der Deutschen Einheit 1, 03046 Cottbus, Germany

^j Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA