▎ 摘　　要

Systematic studies on a recently synthesized nitrogen-doped tetragonal-shaped single crystal graphene (NTSG) recover an orderly growth mechanism, which lead to an undiscovered novel structure of this new kind of nitrogen-doped graphene nanoribbon. The nitrogen atoms, bringing in high spin state depending on the length of the single crystal, endue the NTSG array with special electromagnetic property and possible application in the field of semiconductor. Further examination on oxygen adsorption at NTSG reveals high electrocatalytic activity of NTSG in oxygen reduction reaction, indicating that this nitrogen-doped graphene material could be used as a potential catalyst for hydrogen fuel cells. This work may be helpful for the further research on nitrogen-doped graphene nanoribbon and promoting the development of a new functional device.