Accumulation of localized charge on the surface of polymeric carbon nitride boosts the photocatalytic activity

Abstract The random mobility of charge carriers is a main factor causing the low photocatalytic efficiency of g-C3N4. Thus, the controllable migration of charge carriers is a rational strategy to suppress the charge recombination and facilitate charge separation. Herein, an ethylenediamine modified g-C3N4 displays improved photocatalytic activity. The excellent charge separation efficiency is confirmed to be a key factor for the enhancement. The observation from TEM image after photo-deposited Pt nanoparticles and DFT calculations verify the accumulation of electrons on some area of surface. The increased -NH2 groups significantly tune the electronic structure of g-C3N4 after modification. The generation of midgap state also affect the charge separation. Our reports provide a simple method to manage the migration of charge carriers and enables electrons directional transfer, which suppress the recombination and improve the photocatalytic activity.