title: Enabling Photoemission Electron Microscopy in Liquids via Graphene-Capped Microchannel Arrays.
abstract: Photoelectron emission microscopy (PEEM) is a powerful tool to spectroscopically image dynamic surface processes at the nanoscale, but it is traditionally limited to ultrahigh or moderate vacuum conditions. Here, we develop a novel graphene-capped multichannel array sample platform that extends the capabilities of photoelectron spectromicroscopy to routine liquid and atmospheric pressure studies with standard PEEM setups. Using this platform, we show that graphene has only a minor influence on the electronic structure of water in the first few layers and thus will allow for the examination of minimally perturbed aqueous-phase interfacial dynamics. Analogous to microarray screening technology in biomedical research, our platform is highly suitable for applications in tandem with large-scale data mining, pattern recognition, and combinatorial methods for spectro-temporal and spatiotemporal analyses at solid-liquid interfaces. Applying Bayesian linear unmixing algorithm to X-ray induced water radiolysis process, we were able to discriminate between different radiolysis scenarios and observe a metastable "wetting" intermediate water layer during the late stages of bubble formation.
authors.affiliation: Center for Nanoscale Science and Technology, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.|Maryland NanoCenter, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Hongxuan
authors.initials: H
authors.lastname: Guo
authors.affiliation: Center for Nanoscale Science and Technology, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.|Maryland NanoCenter, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Evgheni
authors.initials: E
authors.lastname: Strelcov
authors.affiliation: Center for Nanoscale Science and Technology, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.|Maryland NanoCenter, University of Maryland , College Park, Maryland 20742, United States.|Department of Materials Science and Engineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Alexander
authors.initials: A
authors.lastname: Yulaev
authors.affiliation: Canadian Light Source, Saskatoon, Saskatchewan S7N 2V3, Canada.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Canadian Light Source, Saskatoon, Saskatchewan S7N 2V3, Canada.
authors.forename: Narayana
authors.initials: N
authors.lastname: Appathurai
authors.affiliation: Department of Chemistry, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C9, Canada.
authors.forename: Stephen
authors.initials: S
authors.lastname: Urquhart
authors.affiliation: Material Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
authors.forename: John
authors.initials: J
authors.lastname: Vinson
authors.affiliation: Center for Nanoscale Science and Technology, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.|Maryland NanoCenter, University of Maryland , College Park, Maryland 20742, United States.|Department of Physics, Oregon State University , Corvallis, Oregon 97331, United States.
authors.forename: Subin
authors.initials: S
authors.lastname: Sahu
authors.affiliation: Center for Nanoscale Science and Technology, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Zwolak
authors.affiliation: Center for Nanoscale Science and Technology, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
authors.forename: Andrei
authors.identifier: 0000-0001-5299-4121
authors.initials: A
authors.lastname: Kolmakov
keywords: PEEM; XAS; data mining; graphene; liquids