▎ 摘　　要

Owing to their unique structural features and surface properties, graphene and nanodiamond have attracted tremendous attention in diverse fields. However, restacking of graphene and reagglomeration of dispersed nanodiamond inevitably depress their catalytic properties. Herein, inspired by the historic discovery of pillared clay, we successfully realized the simultaneous inhibition of their restacking by fabricating a N-doped mesoporous graphene/nanodiamond (N-RGO/ND) nanocomposite by a facile wet-chemical approach. The electrocatalytic oxygen reduction reaction (ORR) and the thermocatalytic oxidant-free and steam-free direct dehydrogenation (DDH) of ethylbenzene were used to examine its catalytic properties. The nanocomposite showed synergistically improved catalytic DDH and electrocatalytic ORR activity relative to that of the individual components, which can be ascribed to synergy between graphene and nanodiamond and to the large surface area, well-ordered mesoporous structure, small crystalline size, and rich defect and CO surface features. Moreover, the developed synthetic strategy in this work can be extended to diverse N-doped nanocomposites from dispersion-required carbon precursors.