| AVS 66th International Symposium & Exhibition | |
| Chemical Analysis and Imaging Interfaces Focus Topic | Thursday Sessions |
| Session CA+2D+AS+BI+NS-ThM |
| Session: | Chemical Analysis and Imaging of Liquid/Vapor/Solid Interfaces II |
| Presenter: | Christopher Arble, National Institute of Standards and Technology (NIST) |
| Authors: | C. Arble, National Institute of Standards and Technology (NIST) H. Guo, Southeast University, China E. Strelcov, National Institute of Standards and Technology (NIST) B. Hoskins, National Institute of Standards and Technology (NIST) M. Amati, Elettra-Sincrotrone Trieste, Italy P. Zeller, Elettra-Sincrotrone Trieste, Italy L. Gregoratti, Elettra-Sincrotrone Trieste, Italy A. Kolmakov, National Institute of Standards and Technology (NIST) |
| Correspondent: | Click to Email |
Assessing chemical processes of electrolyte interfaces under operando conditions is an aspirational goal of great importance to many industrial applications1 that remains technically challenging to investigate. XPS is a powerful characterization tool that can probe elemental and chemical information of atoms with nanoscale depth sensitivity but has traditionally been restricted to UHV conditions. There has been a concerted effort to enable quantitative in-situ measurements of gas and liquid interfaces under realistic environments.2-4 Recently, advances in 2D materials, i.e., graphene, have been utilized to probe heterogenous interfaces through molecularly impermeable, electron transparent membranes to maintain UHV pressure in the analysis chamber.5
Herein we apply photoemission spectromicroscopy to study the electrochemical dynamics of an array of several thousand individual electrolyte cells encapsulated with electron transparent bilayer graphene.6 We monitored the chemical speciation at the electrode- aqueous CuSO4 electrolyte interface as a function of potential. During the electrochemical experiments, the effects of irradiation upon the solution were observed to influence the system, and spectral deconvolution identified oxidized species of copper and oxygen as well as reduced states of sulfur that were connected to reaction pathways tied with radiolysis. Corresponding SEM images and subsequent EDS spectral maps display spatially confided irradiated byproducts which can be associated with the species observed in with XPS.
Observations of XPS spectroscopic regions in the system were taken at varied X-ray dosages to probe the impacts of radiolysis on the liquid solution concerning the spectroscopic observation of electrochemical deposition of Cu. This experimental methodology imparts a greater understanding of the influence of X-ray induced water radiolysis processes towards the quantification of the electrode/electrolyte interfaces and the underlying dosages necessary for artifact-free data acquisition in condensed media.
References:
1. Saveant, J., Chemical Reviews 2008, 108, (7), 2348-2378
2. Siegbahn, H., J. Phys. Chem. 1985, 89, (6), 897-909
3. Salmeron, M.; Schlögl, R., Surf. Sci. Rep. 2008, 63, (4), 169-199
4. Starr, D.; et al., Chem. Soc. Rev. 2013, 42, (13), 5833-5857
5. Kraus, J.; et al., Nanoscale 2014 6, (23), 14394-14403
6. Yulaev, A.; et al., ACS Appl. Mater. Interfaces 2017, 9, (31) 26492-26502