Fixed temperature polymerization during intermediate stage to synthesize highly crystallized g-C3N4 for photocatalytic hydrogen production

Graphitic carbon nitride (g-C 3 N 4 ), owing to its unique structure, has emerged as a hotspot in the semiconductor photocatalytic hydrogen production. However, the intrinsic poor crystallinity of g-C 3 N 4 , which leads to poor hydrogen production efficiency, remains a significant drawback. This study introduces a novel approach for synthesizing highly crystallized g-C 3 N 4 by optimizing precursor mass and employing a fixed temperature polymerization technique. Our research focuses on the intermediate stage polymerization at 220 °C using varying masses of dicyandiamide (DCY) precursors. The results indicate that an increase in the mass of the DCY precursor leads to g-C 3 N 4 with a more regular microstructure and enhanced crystallinity. The photocatalytic hydrogen production rate of this g-C 3 N 4 reached up to 3779 μmol·h −1 ·g −1 , which is five times that of the original g-C 3 N 4 .This research holds significant implications for improving the photocatalytic hydrogen production performance of intrinsic g-C 3 N 4 . Graphical abstract