Synergistic effect triggered by skeleton delocalization and edge induction of carbon nitride expedites photocatalytic hydrogen evolution

[Display omitted] •Substituting bridged N with C atoms and edge grafting heterocycle in CN.•Synergistic effect is triggered by skeleton delocalization and edge induction.•The photocatalytic hydrogen evolution performance is propelled dramatically.•The apparent quantum yield reaches up to 22.4% at 420 nm. The multi-part functionalization of the carbon nitride (CN) molecular skeleton usually induces synergies to boost the photocatalytic activity, but it is a challenging undertaking owing to the uncontrollability in preparation process. Herein, the dual embellished CN is achieved by substituting bridged N with C atoms and grafting conjugated heterocycle on the skeleton edge through facile one-step thermal polymerization. The synergistic effect of skeleton delocalization and edge induction is triggered by the delocalized π bonds from incorporated C atoms and electron-withdrawing function of conjugated heterocycle, which importantly promotes the charge mobility and electron directional migration from center to edge of CN skeleton. The resulted photocatalytic hydrogen evolution (PHE) performance is propelled dramatically and the apparent quantum efficiency (AQE) reaches up to 22.4% at 420 nm. This work launches a typical exemplification for the high-efficiency photocatalytic application of conjugated polymer photocatalysts by triggering synergistic effect of multi-part functionalization.