Fig. 2: Electronic structure characterizations.

a High-resolution XPS spectra for Ni 2p of S-NiBDC and NiBDC. b High-resolution XPS spectrum for S 2p of S-NiBDC. c Ni K-edge XANES and d k3-weighted EXAFS spectra of NiBDC, S-NiBDC, Ni foil, NiO, and NiS. e WT-EXAFS spectra of NiBDC, S-NiBDC, NiO, and NiS. f S K-edge XANES spectra of NiS and S-NiBDC. g Fourier transform-EXAFS fitting results of S-NiBDC.