Fig. 8 (a, b) HRTEM images of CoNi@NC, showing the graphene shells and encapsulated metal nanoparticles. (c) Schematic illustration of the CoNi@NC structure. (d) Statistical analysis of the number of layers in the graphene shells encapsulating the metal nanoparticles in CoNi@NC. (e~h) HAADF-STEM image and corresponding elemental mapping images of CoNi@NC. (i) Gibbs free energy (ΔG) profile of the HER on various catalysts. (j) Volcano plot of the polarized current (i0) versus ΔG(H*) for a CoNi cluster, CoNi@C, and an N-doped graphene shell (Ncarbon)[83]
Other figure/table from this article
