fig2
Figure 2. (A) shows the comparison of XRD patterns for NH, CH, NCH1, NCH2 and NCH3 samples; (B-F) show the XPS spectra measurements of C 1s, O 1s, Ni 2p and Co 2p for NCH1, respectively. XRD: X-ray diffraction; NH: nickel-only material; CH: cobalt-only material; NCH1: nickel-cobalt hybrid material (Ni2+:Co2+ = 1:3); NCH2: nickel-cobalt hybrid material (Ni2+:Co2+ = 3:1); NCH3: nickel-cobalt hybrid material (Ni2+:Co2+ = 1:1); XPS: X-ray photoelectron spectroscopy.
