Regulation of the Tertiary N Site by Edge Activation with an Optimized Evolution Path of the Hydroxyl Radical for Photocatalytic Oxidation

Regulating the active sites to increase the yield of •OH is a specialized focus for pollutant photodegradation by g-C3N4-based photocatalysts. Herein, the tertiary N site was first tailored by edge activation to optimize the •OH evolution path. Ethyl alcohol and cyano group comodified g-C3N4 was first fabricated via a facile one-pot thermal copolymerization route to achieve a high yield of •OH. The as-prepared N20–CN exhibited first-class photocatalytic oxidation ability in the degradation of phenol (k40 min is 26.3 times higher than that of BCN). Both experimental results and DFT calculations disclose that the tertiary N site with increased electron density via synergy of the two groups realizes not only the oxygen reduction route mediated with •O2– but also the in situ conversion of H2O2 between high production and strong reduction, governing the O2 → •O2– → H2O2 → •OH optimal evolution path with a high yield of •OH. This paper provided a theoretical basis for the development of a superactive g-C3N4-based photocatalyst and optimization of •OH evolution paths via the edge activation strategy for solar-driven photochemical applications.