In situformation of 2-thiobarbituric acid incorporated g-C3N4for enhanced visible-light-driven photocatalytic performance

Abstract

Embedding heterocycles into the skeleton of g-C3N4has been proved to be a simple and efficient strategy for improving light response and the separation of photo-excited charges. Herein, 2-thiobarbituric acid incorporated g-C3N4(TBA/CN) with good photocatalytic efficiency for Rh B degradation and H2production was successfully achievedviaa facile thermal copolymerization approach. The incorporation of aromatics and S atoms into the skeleton of g-C3N4was identifiedviasystematic characterizations. This unique structure contributed to the narrowed band-gap, extended delocalization of lone pair electrons and changed electron transition pathway, which led to the enhanced visible light utilization, accelerated charge migration and prolonged electron lifetime, subsequently resulting in the significant boost of photocatalytic activity. The optimal TBA/CN-3 sample yielded the largest Rh B degradation rate constantkvalue of 0.0273 min−1and simultaneously highest rate of H2evolution of 0.438 mmol g−1h−1, which were almost 3.5 and 3.8 folds as fast as that of the pristine CN, respectively. Finally, the photocatalytic mechanism was proposed for the detailed elucidation of the process of Rh B degradation coupled with H2production.