Facile synthesis of porous C-doped C3N4: fast charge separation and enhanced photocatalytic hydrogen evolution†
Metal-free graphitic carbon nitride (g-C3N4) is a promising semiconductor material that can utilize visible light for photocatalytic hydrogen production. The photocatalytic activity can be further enhanced by improving the kinetics of photocarrier transfer and absorption efficiency of visible light. Herein, we demonstrate a facile strategy for the synthesis of C-doped g-C3N4 with porous hierarchical structure by simple co-pyrolyzation of acrylamide and dicyandiamide together. The addition of trace amount of acrylamide not only endows g-C3N4 with high porosity and specific surface area, but also promotes electron–hole separation and charge transfer due to the introduction of carbon dopant into the g-C3N4 structure. With 2 wt% of acrylamide in the precursor, the resulted C-doped g-C3N4 can deliver 3.4 times higher photocatalytic activity for hydrogen evolution than that of the bulk g-C3N4. Our present work provides valuable information for the performance-based optimization of composition and structural properties, as well as large scale production of high performance g-C3N4 photocatalysts.