Controllable macroscopic polarization induced asymmetric electron distribution in poly (heptazine imide) for enhanced...

The incorporation of carbon nitride into photocatalytic technology creates a sustainable and pollution-free method for producing hydrogen peroxide (H₂O₂). Unfortunately, the efficiency of this process is greatly hindered by the sluggish separation of photo-generated carriers due to the weak internal electrical potential. To overcome this limitation, we present a promising strategy involving the fabrication of O-modulated poly(heptazine imide) (O-PHI), achieved through solid phase self-assembly aided by KSCN. This unique electron-rich polarization electric field induces asymmetric electron distribution, greatly enhancing the charge dynamics and facilitating enhanced photo-generated electron injection into active sites. As a result, when combined with CN units and oxygen functionalities that enhance oxygen adsorption, O-PHI exhibits superior H₂O₂ photosynthesis with a remarkable yield of 17.0 mmol g^-1h^-1 in pure water through both oxygen reduction and water oxidation routes, even up to 321.7 mmol g^-1h^-1 using a sacrificial reagent. These remarkable results demonstrate that the electron-rich polarization electric field outperforms the electron-deficient counterpart in H₂O₂ photosynthesis, surpassing the best known photocatalysts. This research represents a significant advancement in electron modification technology, leading to the design of more efficient metal-free photocatalysts for the production of valuable fuels.