Fig. 1: Morphology and crystalline characterizations.

a Schematic illustration of synthesizing ac-Ni(OH)2@m-Pt catalyst. (b) XRD patterns of m-Pt and ac-Ni(OH)2@m-Pt. (c) TEM, (d) local enlargement of (c) (the yellow circles represent mesoporous structures), and (e) HRTEM images of ac-Ni(OH)2@m-Pt. f, g Enlarged images and the corresponding FFT patterns of the selected regions marked by the blue and orange squares, respectively, in (e). h EDX element mappings of ac-Ni(OH)2@m-Pt catalyst.