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

Graphitic carbon nitride (g-C₃N₄), owing to its unique structure, has emerged as a hotspot in the semiconductor photocatalytic hydrogen production. However, the intrinsic poor crystallinity of g-C₃N₄, which leads to poor hydrogen production efficiency, remains a significant drawback. This study introduces a novel approach for synthesizing highly crystallized g-C₃N₄ 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-C₃N₄ with a more regular microstructure and enhanced crystallinity. The photocatalytic hydrogen production rate of this g-C₃N₄ reached up to 3779 μmol·h⁻¹·g⁻¹, which is five times that of the original g-C₃N₄.This research holds significant implications for improving the photocatalytic hydrogen production performance of intrinsic g-C₃N₄.