TY - JOUR

T1 - Surface dynamics of mixed silver-copper oxide AgCuO2 during X-ray photoelectron spectroscopy study

AU - Svintsitskiy, Dmitry A.

AU - Yu. Kardash, Tatyana

AU - Boronin, Andrei I.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - A detailed study of mixed silver-copper oxide AgCuO2 was performed using X-ray photoelectron spectroscopy. The state and ratio of elements on the surface at different probing depth was revealed using variable radiation energy. A non-uniform in-depth distribution of silver and copper states was established. Two silver states were detected on the initial surface: (1) highly oxidized Ag>1+ ions from AgCuO2 lattice and (2) impurity Ag0 metallic species. The appearance of metallic species was related to AgCuO2 surface reduction by adsorbed carbon admixtures during air-storage. It was shown that highly oxidized copper species can be identified by the analysis of shake-up satellites in Cu2p region during step-by-step exposure to X-rays. This approach, considering all spectral changes versus time, allowed us to reveal the presence of copper with the oxidation level higher than +2 on the initial AgCuO2 surface. It was found that a long-term exposure to intense X-rays significantly modifies the composition and state of the AgCuO2 surface. Possible causes of such modification are discussed in relation to the AgCuO2 reaction properties.

AB - A detailed study of mixed silver-copper oxide AgCuO2 was performed using X-ray photoelectron spectroscopy. The state and ratio of elements on the surface at different probing depth was revealed using variable radiation energy. A non-uniform in-depth distribution of silver and copper states was established. Two silver states were detected on the initial surface: (1) highly oxidized Ag>1+ ions from AgCuO2 lattice and (2) impurity Ag0 metallic species. The appearance of metallic species was related to AgCuO2 surface reduction by adsorbed carbon admixtures during air-storage. It was shown that highly oxidized copper species can be identified by the analysis of shake-up satellites in Cu2p region during step-by-step exposure to X-rays. This approach, considering all spectral changes versus time, allowed us to reveal the presence of copper with the oxidation level higher than +2 on the initial AgCuO2 surface. It was found that a long-term exposure to intense X-rays significantly modifies the composition and state of the AgCuO2 surface. Possible causes of such modification are discussed in relation to the AgCuO2 reaction properties.

KW - AgCuO

KW - High-valent copper

KW - Mixed silver-copper oxide

KW - Synchrotron radiation

KW - XPS

UR - http://www.scopus.com/inward/record.url?scp=85052447708&partnerID=8YFLogxK

U2 - 10.1016/j.apsusc.2018.08.234

DO - 10.1016/j.apsusc.2018.08.234

M3 - Article

AN - SCOPUS:85052447708

VL - 463

SP - 300

EP - 309

JO - Applied Surface Science

JF - Applied Surface Science

SN - 0169-4332

ER -