Few-Layer Meets Crystalline Structure: Collaborative Efforts for Improving Photocatalytic H₂O₂ Generation over Carbon...

Although the conversion of O₂ and H₂O to H₂O₂ over graphite carbon nitride (g-C₃N₄) has been realized by means of the photocatalytic process, the catalytic activity of pristine g-C₃N₄ is still restricted by the rapid charge recombination and inadequate exposure of the active site. In this work, we propose a straightforward strategy to solve these limitations by decreasing the thickness and improving the crystallinity of g-C₃N₄, resulting in the preparation of few-layered crystalline carbon nitride (FL-CCN). Benefiting from the minimal thickness and highly ordered in-plane triangular cavities within the structure, FL-CCN processes an extended π-conjugated system with a reduced charge transfer resistance and expanded specific surface area. These features accelerate the efficiency of photogenerated charge separation in FL-CCN and contribute to explore of its surface active sites. Consequently, FL-CCN exhibits a significantly improved H₂O₂ evolution rate (63.95 μmol g^-1 h^-1), which is 7.8 times higher than that of pristine g-C₃N₄ (8.15 μmol g^-1 h^-1), during the photocatalytic conversion of O₂ and H₂O. This systematic investigation offers valuable insights into the mechanism of photocatalytic H₂O₂ generation and the development of efficient catalysts.