Fig. 2: Structural characterizations of Ni-Co-P/NF and reference samples.

a XRD patterns of Ni-Co-P/NF; High-resolution XPS spectra of b Co 2p; c Ni 2p; d P 2p for the prepared samples; e Co and f Ni K-edge XANES spectra of Ni-Co-P/NF and the reference compounds; g the left and right correspond to the squared areas in (e) and (f), respectively; EXAFS results of (h) Co K-edge; (i) Ni K-edge for Ni-Co-P/NF and the reference compounds.