Fig. 4. X-ray absorption near edge structure spectra (Ni K edge) of the Ni–CNT material as prepared (black solid line), and after 1 h H₂ oxidation (red solid line). Spectra of pristine (blue dotted line) and of [Ni(OH₂)₆]²⁺ (orange dotted line) are shown for comparison. See Fig. S10† for a magnification of the K edge region.