▎ 摘　　要

MoS2 nanodots (NDs) were successfully embedded in the three-dimensional (3D) porous frameworks of N-doped graphene (NGr) via in situ pyrolysis of glucose, a layered C3N4 sacrificial template and monolayered MoS2 NDs. The monolayered MoS2 NDs were hydrothermally pre-synthesized and acted as size-controlled precursors. By varying the content of the MoS2 NDs, a series of MoS2 NDs/NGr was obtained, which displayed amendable activity towards oxygen reduction reaction (ORR) in basic solution, due to the balance between the exposed edge sites of the MoS2 NDs and the internal conductive channels of the 3D porous NGr. The optimal composition generated an efficient Pt-free ORR catalyst with good four-electron selectivity, and was shown to have a more positive shift in both the onset and peak potentials than its counterparts. The novel catalyst also demonstrated superior tolerance against methanol and better durability than commercial Pt/C.