Limbic Inducted and Delocalized Effects of Diazole in Carbon Nitride Skeleton for Propelling Photocatalytic Hydrogen Evolution

Skeleton modification on carbon nitride (g-C3N4) via organic molecules is a recognized effective strategy to improve photocatalytic performance because it can powerfully improve charge separation in the skeleton plane. Herein, a diazole with a unique conjugated structure is bonded on edge of the g-C3N4 skeleton through a moderate polymerization of urea with 4-aminoantipyrine (4AAP). Meanwhile, the Pt nanoparticles selectively deposit on edge of the g-C3N4-4AAP15 nanosheet. It reveals that the robust limbic inducted and delocalized effects of diazole not only facilitate photogenerated electrons aggregation toward skeleton edge to promote in-plane carrier separation but also effectively stabilize and delocalize photogenerated electrons to improve carrier lifetime for propelling the photocatalytic hydrogen evolution (PHE) reaction. Specifically, the PHE rate over optimal g-C3N4-4AAP15 (284.2 μmol h-1) is 10 times that of pure g-C3N4 (27.6 μmol h-1) and the apparent quantum efficiency (AQE) at 420 nm reaches up to 24.2%. Through insights into the functionalized effect of small nitrogenous heterocycles introduced into the skeleton edge of g-C3N4, this work opens a new design thought for exploiting high-efficiency g-C3N4-based photocatalysts for photocatalytic application.