Nitrogen vacancies-engineered graphitic carbon nitride nanosheets for boosting photocatalytic H2 production

Defect engineering can be considered a powerful strategy for enhancing photocatalytic performance. Here, we successfully synthesized tri-coordinated nitrogen vacancies-modified graphitic carbon nitride (Nv-GCN) by employing a simple sintering process. The optimized Nv-GCN shows boosted photocatalytic H2 production (5.45 mmol g−1 h−1) in comparison with that of the pristine GCN (0.69 mmol g−1 h−1) under visible light irradiation. It is found that the nitrogen vacancies provide more active sites in photocatalytic reactions. Meanwhile, the electronic structure of Nv-GCN can be modulated by nitrogen vacancies, and defect levels are formed in the intrinsic bandgap. The introduced nitrogen vacancies not only broaden the range of visible-light absorption and narrow the band gap of GCN but also accelerate the separation and transfer of the photogenerated charges. This study provides an effective route for designing high-performance photocatalysts for highly efficient conversion of solar energy.