Subsurface oxygen in oxide-derived Cu is evidenced by X-ray photoelectron spectroscopy, as reported by Hsin-Yi Wang et al. in their Research Article (DOI: 10.1002/anie.202111021). The results point out that after reducing the Cu oxide precursor, two types of oxygen species, (i) oxygen staying at lattice defect and/or vacancies in the surface-most region and (ii) interstitial oxygen intercalated in metal structure, are embedded between the fully reduce metallic surface and the Cu₂O buried beneath. This study adds the convincing support for the subsurface oxygen formation.

中文翻译：

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通过 X 射线光电子能谱法直接证明氧化物衍生的铜中形成亚表面氧

正如 Hsin-Yi Wang 等人报道的那样，X 射线光电子能谱证明了氧化物衍生的 Cu 中的亚表面氧。在他们的研究文章中（DOI：10.1002/anie.202111021）。结果指出，在还原 Cu 氧化物前体后，两种类型的氧物种，（i）停留在最表面区域的晶格缺陷和/或空位处的氧和（ii）插入金属结构中的间隙氧，嵌入在完全还原的金属表面和埋在下面的 Cu ₂ O。这项研究为地下氧气的形成提供了令人信服的支持。