Fig. 5: Structural analysis of the NiSA-O/Mo2C after HER/OER to study active sites.

a, b HRTEM images of NiSA-O/Mo2C after HER/OER stability tests. c–e Ex situ Mo k-edge XANES and the corresponding FT-EXAFS curve of NiSA-O/Mo2C, NiSA-O/Mo2C-OCP, and NiSA-O/Mo2C after HER/OER. f–g Ex situ XAS spectra of Ni K-edge of NiSA-O/Mo2C and the corresponding FT- EXAFS spectra after HER/OER, respectively. h HAADF-STEM image and EDS element mapping of NiSA-O/Mo2C after OER.