Optical Fluorescence Detected from X-ray Irradiated Liquid Water

Andreas Hans, Christian Ozga, Robert Seidel, Philipp Schmidt, Timo Ueltzhöffer, Xaver Holzapfel, Philip Wenzel, Philipp Reiß, Marvin N. Pohl, Isaak Unger, Emad F. Aziz, Arno Ehresmann, Petr Slavíček, Bernd Winter, André Knie

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Despite its importance, the structure and dynamics of liquid water are still poorly understood in many apsects. Here, we report on the observation of optical fluorescence upon soft X-ray irradiation of liquid water. Detection of spectrally resolved fluorescence was achieved by a combination of the liquid microjet technique and fluorescence spectroscopy. We observe a genuine liquid-phase fluorescence manifested by a broad emission band in the 170-340 nm (4-7 eV) photon wavelength range. In addition, another narrower emission near 300 nm can be assigned to the fluorescence of OH (A state) in the gas phase, the emitting species being formed by Auger electrons escaping from liquid water. We argue that the newly observed broad-band emission of liquid water is relevant in search of extraterrestrial life, and we also envision the observed electron-ejection mechanism to find application for exploring solutes at liquid-vapor interfaces. (Figure Presented).

Original languageEnglish
Pages (from-to)2326-2330
Number of pages5
JournalJournal of Physical Chemistry B
Issue number10
Publication statusPublished - 16 Mar 2017

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