Fig. 2. (a and b) SEM micrographs of Nb₂CT_x MXene & Ni–Nb₂CT_x MXene, respectively, (c) TEM images of Ni–Nb₂CT_x MXene show a particle fabricated at low magnification (d) and (e) show high resolution images of the periphery of the same particle; the inset in (d) is the fast Fourier transform of the image indicating the hexagonal symmetry of the sample, (f–h) elemental mapping of Ni-doped Nb₂CT_x MXene.