fig2
Figure 2. (A) PXRD patterns; (B) Ni 2p XPS spectra; (C) N 1s XPS spectra and (D) C 1s XPS spectra of NiOx@DG and NiOx-DG; (E) EPR spectra of NiOx@DG; (F) Raman spectroscopy of NiOx@DG. PXRD: Powder X-ray diffraction; XPS: X-ray photoelectron spectroscopy; DG: defective graphene.
