Introduction of the -B(OH)₂ group into a graphene motif for p_z orbital removal and ferromagnetic modulation

Room-temperature ferromagnetism in graphene has attracted considerable attention due to its potential application as spintronics. Theoretically, magnetic moment of graphene can be generated by removing a single p_z orbital from the π system, which introduces an unpaired electron into the graphene motif for magnetic coupling. In this work, p_z orbital of graphene is experimentally removed by cleaving the π bond of graphene using H₃BO₃ with the assistance of supercritical CO₂ (SC CO₂), which simultaneously introduces -B(OH)₂ groups and unpaired electrons. As a result, ferromagnetic coupling between unpaired electrons substantially enhances the magnetic properties of the 2D graphene motif, leading to room-temperature ferromagnetism. Overall, unpaired electrons were introduced into a 2D graphene motif through π bond cleavage, which provides a novel approach for magnetic manipulation of 2D materials with conjugated structures.