▎ 摘　　要

Band gap opening and engineering make up one of the primary goals of developing novel materials for photocatalytic hydrogen generation. We report here a facile synthesis of graphene decorated with in-plane boron nitride domains via control of both the doping sequence of heteroatoms and the oxygen content of the graphene precursor, showing significant differences in the doping pattern compared with B and/or N singly doped or co-doped graphene. We uncover that the formation of BN domains in graphene is critical for engineering the band gap and delivering an improved activity for photocatalytic hydrogen generation in the absence of any photosensitizer. This work paves the way for the rational design and construction of graphene-based photocatalysts for efficient photo catalysis.