Interface Engineering of Polymeric Carbon Nitride with Enhanced Charge Separation for Efficient Visible Light Photosynthesis of Hydrogen Peroxide from Oxygen and Water

Abstract Photosynthesis of H ₂ O ₂ from O ₂ and H ₂ O with inexhaustible sunlight as an energy source is a promising approach. However, the photocatalytic performance of pristine polymeric carbon nitride (PCN) is extremely restrained due to the rapid recombination of photo‐generated electrons and holes, and slow surface reaction processes. Herein, a new strategy is developed to rationally integrate N, S‐co‐doped carbon (C _NS ), and CoS ₂ on cyano‐rich PCN (PCN‐Cy) for photosynthesis of H ₂ O ₂ under ambient conditions. The engineering with cyano groups (electron‐withdrawing groups) promotes the bulk charge separation of PCN. Experimental results reveal that the CoS ₂ co‐catalyst not only serves as an electron acceptor to extract charges from the bulk but also functions as an active site to promote the 2‐e ⁻ ORR process. Besides, the N, S‐co‐doped carbon performs as an electron channel to promote migration of charges at the interface of PCN‐Cy and CoS ₂ . Accordingly, the as‐synthesized cyano‐rich PCN photocatalyst integrated with N, S‐co‐doped carbon and CoS ₂ exhibits a remarkable activity of 321.9 µ m h ⁻¹ for photocatalytic production of H ₂ O ₂ , which is 44.9 times higher than that of the pristine PCN.