Stitching electron localized heptazine units with “carbon patches” to regulate exciton dissociation behavior of carbon nitride for photocatalytic elimination of petroleum hydrocarbons

Abstract

The electron localized heptazine units make it difficult to separate photoinduced electeron-hole pairs for graphitic carbon nitride (g-C3N4), which limits the application prospect of graphitic-like carbon nitride. Changing inherent N-(C)3 bridging mode of in-plane heptazine units and built more electron channel could be a reasonable strategy. Herein, “carbon patches” were introduced to stitch heptazine units, high speed electron transfer path were thus constructed due to delocalized p orbital electron in “carbon patches” as a result. Simultaneously, interlayers’ high speed electron transfer channel was also constructed by distorted molecular layer because of presence of large electronegative interstitial phosphorus atoms. Such photoinduced electron-holes’ spatial separation in-plane and interlayers were built concurrently and confirmed by XANES and DFT calculation for the first time. The resulted PCCNv series photocatalysts exhibited superior photon absorption capability, excellent charge carriers’ separation kinetics, good O2 molecule adsorption as well as activation capability, the resulted abundant reactive radicals contributed to petroleum hydrocarbons photocatalytic degradation significantly. This work shed light on efficient separation of photoinduced excition for carbon nitride in photocatalysis, simultaneously presented a promising candidate non-metal photocatalytic environmental material for marine oil spill remediation.