Boosting the photocatalytic hydrogen production performance of graphitic carbon nitride nanosheets by tailoring the cyano groups

Graphitic carbon nitride (g-C3N4) is a promising visible light responsive photocatalyst for solar hydrogen production. However, pristine g-C3N4 suffers from severe charge recombination, resulting in a poor photocatalytic activity. Herein, a facile KOH-assisted sealed heating process is designed to tailor the electronic structure of g-C3N4, leading to a significantly enhanced and stable photocatalytic hydrogen production rate of 225.1 µmol h-1 using only 50 mg of the photocatalyst. An excellent apparent quantum efficiency of 16.82% is achieved at 420 nm. Systematic studies reveal that KOH-assisted sealed heating can generate more cyano groups onto the framework of g-C3N4, which can increase the charge carrier density and reduce the surface charge transfer resistance, promoting charge separation and transfer. The new findings demonstrated in this work provide a facile strategy for the design of low-cost and efficient photocatalyst for solar fuel production.