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Enabling photoemission electron microscopy in liquids via graphene-capped microchannel arrays



Hongxuan Guo, Evgheni Strelcov, Alexander Yulaev, Jian Wang, Narayana Appathurai, Stephen Urquhart, John Vinson, Subin Sahu, Michael P. Zwolak, Andrei Kolmakov


Photoelectron emission microscopy (PEEM) is a powerful tool to spectroscopically access dynamic surface processes at the nanoscale but is traditionally limited to ultra-high or moderate vacuum conditions. Here, we develop a novel graphene-capped multichannel array platform that extends the capabilities of photoelectron spectro-microscopy, allowing for routine liquid and atmospheric pressure studies with standard PEEM setups. At the water-graphene interface, the XAS spectra at the oxygen K edge reveals that graphene has only a minor influence on the electronic structure of water in the first few layers, an ideal scenario for examining unperturbed aqueous-phase dynamics at the interface. Similar to microarray screening in biomedical research, our platform is suitable for application in tandem with large-scale data mining, pattern recognition, and combinatorial methods for spectro-temporal and spatiotemporal analyses at solid-liquid interfaces. Using these algorithms, we characterize the behavior of radiolysis products in water and observe a metastable "wetting" water layer during the late stages of bubble formation.
Nano Letters


Photoelectron emission microscopy, in operando, atmospheric pressure and liquids


Guo, H. , Strelcov, E. , Yulaev, A. , Wang, J. , Appathurai, N. , Urquhart, S. , Vinson, J. , Sahu, S. , Zwolak, M. and Kolmakov, A. (2017), Enabling photoemission electron microscopy in liquids via graphene-capped microchannel arrays, Nano Letters, [online],, (Accessed June 18, 2024)


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Created February 7, 2017, Updated October 12, 2021