VN Quantum Dots Anchored Uniformly onto Nitrogen-Doped Graphene as Efficient Electrocatalysts for Oxygen Reduction Reaction

A new type of vanadium nitride quantum dots anchored homogeneously onto nitrogen-doped graphene (VNQD-NG) is fabricated as nonprecious metal-based electrocatalysts for ORR via a combined hydrothermal and ammonia annealing process. The unique structural features of VNQD-NG including plentiful VN quantum dots with the sizes of 3-6nm, high surface area and multi-level pores afford considerable structural edges and defects as active sites, maximizing the exposed active sites and providing sufficient electron transport pathways for ORR. Hence, the optimized VNQD-NG exhibits high electrocatalytic activity, long durability and high selectivity for ORR, better than commercially available Pt-C.