The near-edge structure of the XAS spectra (XANES) is useful for chemical fingerprinting of oxidation state and geometry. XANES of the 61 NiPACN samples show features at 8334 eV and 8340 eV and a small shift of the edge to lower energies for the 1 wt% sample, consistent with a more reduced Ni environment (Figure ). Comparing these spectra to XANES of metallic Ni and a molecular square planar complex, Ni Phthalocyanine (NiPc), shows the existence of a sharp 1s→4p feature at 8340 eV which is characteristic of square planar geometries and the dipole forbidden 1s→3d peak at 8334 eV which has higher intensity in reduced symmetry environments (Figure ). The derivative XANES spectra demonstrate that the 1s→4p feature (8340 eV) exists in the 61 NiPACN samples which supports the existence of a square planar-like geometry of Ni atoms in agreement with prior reports (Figure ). In addition, the size of this feature decreases and the metallic-like peak at 8334 eV grows for the 1 wt% sample which is consistent with increasing Ni aggregate character for that sample. The extended XAS fine structure (EXAFS), originating from the scattering of photoelectrons off neighboring atoms, gives direct information of the bonding environment in the samples (Figure , 4F, k-space plot in SI-Figure ). The main prominent feature for the 0.1 wt% sample is at 1.29 Å which agrees well with the Ni-N scattering peak for NiPc at 1.38 Å. The 0.5 wt% also shows this Ni-N peak and a second peak at 2.48 Å that likely corresponds to the carbon atoms in the secondary coordination shell. Consistent with all the prior observations, the 1 wt% sample shows a prominent peak at 2.22 Å which roughly matches the primary peak at 2.15 Å for metallic Ni. The 1 wt% sample also has the first coordination peak at 1.26 Å which could represent both dispersed NiNx sites or oxidized Ni that exists along with metallic Ni.