High-polycondensation and porous carbon nitride nanosheets for highly efficient photocatalytic hydrogen evolution

Abstract

The degree of polycondensation (DP) has significantly affected the physical and chemical performance of polymeric graphitic carbon nitride (PCN), especially in optimizing the electronic structure and surface chemical properties, thus regulating DP is a promising strategy for improving the photocatalytic performance of graphitic carbon nitride. This investigation supplies a facile procedure, step-by-step polymerization, to synthesize porous carbon nitride nanosheets (PCNNs) with different DP. The PCNNs revealed an uplifted visible-light-driven (λ ˃ 420 nm) photocatalytic hydrogen evolution rate of 415.6 μmol/h/g, which is approximately 7.3-fold higher than that of PCN. The increased activity of PCNNS would be originated from the porous structure with good hydrophilicity and the higher DP of the heptazine unit facilitating the separation and transport of photoexcited carriers. This work successfully demonstrates a prospective post-synthesis strategy effective for boosting the performance of graphitic carbon nitride.