Self-introduction of carbon nitride quantum dots into carbon nitride planar structure for enhanced photocatalytic hydrogen production

The separation efficiency and migration rate of photogenerated carriers are important factors determining the activity of photocatalysts. In this work, CN/CNQDs were prepared by self-introducing carbon nitride quantum dots (CNQDs) into the planar structure of carbon nitride (CN) using a novel photo-triggered self-assembly strategy. Different from conventional interfacial modification strategies based on van der Waals forces or hydrogen bonding, CN/CNQDs atomic junctions formed chemical bonds between the two components, which have stronger interfacial interactions and facilitate efficient carrier migration between the two components. The continuous π-conjugated structure of CN/CNQDs also provided unique conditions for carrier migration. In addition, the presence of in-plane electric field (IEF) in CN/CNQDs acted as a direct driving force for the migration of electrons and holes in the opposite directions, which greatly facilitates the separation and transfer of photogenerated carriers in CN/CNQDs. This work provides an atomic-level strategy for the construction of heterojunction photocatalyst systems.