▎ 摘　　要

Development of graphene-like nanocarbons with a 3D interlinked porous structure has gained much interest due to their synergetic merits combining 2D morphology with porous architectures. Herein, a novel kind of graphene-like nanocarbon is prepared via a simple, relatively cost-efficient and scalable strategy, by using the biomolecule guanine as the precursor combined with a facile CO2 activation procedure. The as-prepared materials not only have in situ high-level nitrogen doping and defect-enriched properties, but also possess a unique 3D architecture constituted by the interconnection of ultrathin and curly carbon nanosheets. These synergistic advantages of a 3D hierarchically porous structure, a large surface area, a high content of active nitrogen species, abundant defect sites and a unique graphene-like architecture, thus endow the materials with excellent catalytic activity, methanol immunity and long-term stability for the ORR under both acidic and alkaline conditions, very comparable and even superior to those of a Pt/C catalyst. This work is expected to provide a facile but efficient strategy for large-scale preparation of graphene-based materials, and meanwhile inspire an idea for developing more efficient electrocatalysts.