Abstract: The unique structural features and remarkable physicochemical properties of graphdiyne (GDY) have made it an attractive contender in photocatalysis. The strategic incorporation of heteroatoms into GDY enables precise modulation of its band structure while creating additional active sites. Herein, nitrogen-doped triazine-based graphdiyne (TA-GDY) was successfully synthesized via a controlled process and subsequently combined with ZnCdSe to construct an S-scheme heterojunction. Combined experimental characterizations and theoretical calculations demonstrate that this heterostructure remarkably facilitates the transfer and spatial separation of photogenerated carriers, meanwhile maintaining a strong redox potential, leading to substantially enhanced photocatalytic hydrogen evolution performance. Under 300 W xenon lamp irradiation (λ<420 nm), the ZnCdSe/TA-GDY composite demonstrates a remarkable hydrogen production rate of 37.31 mmol∙g^-1∙h^-1, representing 5.5 times and 219.5 times enhancements compared to those of ZnCdSe (6.74 mmol∙g^-1∙h^-1) and TA-GDY (0.17 mmol∙g^-1∙h^-1), respectively. Furthermore, the addition of TA-GDY can reduce the photocorrosion phenomenon in the ZnCdSe semiconductor, making ZnCdSe/TA-GDY more stable. The study provides fresh methods and concepts for creating enduring and efficient photocatalytic materials.

Key words: S‐Scheme heterojunction, Graphdiyne, Nitrogen‐ doped, Photocatalytic hydrogen evolution, ZnCdSe