Supramolecular assembly promoted synthesis of three-dimensional nitrogen doped graphene frameworks as efficient electrocatalyst for oxygen reduction reaction and methanol electrooxidation

Three dimensional hierarchical nitrogen-doped graphene aerogel networks were successfully fabricated through a supramolecular assembly-assisted method. The designed metal-free sample exhibits not only impressive catalytic performance for oxygen reduction closely comparable with Pt/C of the similar quantity, but also excellent catalytic activity and stability for methanol electrooxidation when served as support of Pt nanoparticles. [Display omitted] •3D nitrogen-doped graphene is synthesized through a supramolecular assembly-assisted method.•Supermolecule melamine-cyanurate perform as both N source and self-sacrificial pore forming agent.•Supermolecular aggregates play a vital role in inducing the formation of unique 3D architecture.•NGA exhibits comparable ORR catalytic activity to that of commercial Pt/C.•Pt/NGA displays excellent catalytic activity and stability for methanol electrooxidation. Nitrogen-doped three-dimensional porous graphene frameworks (NGAs) are fabricated through a unique strategy of adopting the supramolecular assembly-assisted method with GO as building block, and supramolecular aggregate of self-assembled melamine and cyanuric acid as not only a “spacer” to suppress the re-stacking of graphene nanosheets but a self-sacrificial pore-forming agent as well as a nitrogen source leading to simultaneous N-doping. Supramolecular aggregates function as the structure-directing agent playing a vital role in generating the loose porous and free-stacking structure and guiding the formation of unique 3D architecture. The resulting metal-free NGA products possess high specific surface area, porous structure and free-stacking properties, and exhibit enhanced ORR performance in terms of positive half-wave potential which is only ∼43 mV lower than that of a commercial Pt/C, four-electron-transfer process, good durability and outstanding methanol poisoning tolerance. Besides, it also performs as a good support for Pt particles. Consequently, Pt/NGA catalyst displays impressive catalytic activity and stability towards efficient methanol electrooxidation reaction. This simple and robust synthetic strategy of 3D N-doped graphene has put forward a new prospect for rational synthesis of heteroatoms doped carbon materials for sustainable energy conversion applications.