Figure 9.

(a) Room‐temperature ESR spectra and (b) schematic illustrating the locations of oxygen vacancies in WO₃ lattice. Reproduced from Ref. [76] with permission from American Chemical Society, Copyright 2016. (c) Raman spectra at the excitation wavelength of 325 nm of Co₃O₄‐p and OV‐Co₃O₄. Reproduced from Ref. [79] with permission from American Chemical Society, Copyright 2019. (d) FT spectra at the Co K‐edge for B‐doped CoO−Ov, CoO, and standard Co(OH)₂. Reproduced from Ref. [24] with permission from WILEY‐VCH Verlag GmbH&Co. KGaA, Weinheim, Copyright 2018. (e) Surface‐sensitive TEY sXAS scans at the O K‐edge of L−CO, LN−CO, C−CO, CN−CO, and reference CoO, Co₂O₃. The emerging new peak at approximately 533.5 eV on the spectra of L−CO and LN−CO refers to oxygen vacancy. Reproduced from Ref. [81] with permission from WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim, Copyright 2019.