Fig. 2: Structural characterization.

a XPS spectra of Mo 3d. b XPS spectra of Ni 2p. c Mo K-edge XANES spectra. Inset in (c) is the partial enlargement of the pre-edge peak. d The FT-EXAFS curves for the as-prepared samples. e Ni K-edge spectra. f The corresponding FT-EXAFS curve. g The wavelet transform (WT) of the NiSA-O/Mo2C. h, i Ni K-edge EXAFS of NiSA-O/Mo2C in R and k spaces.