Nitrogen vacancy-rich porous carbon nitride nanosheets for efficient photocatalytic H 2 O 2 production

Photocatalytic production of H 2 O 2 has attracted widespread attention as an environmental-friendly approach. However, the low activity and selectivity of photocatalytic H 2 O 2 are still unsatisfactory. In this work, we connected the triblock copolymer, melamine, and melinic acid by hydrogen bonding through supramolecular self-assembly. The triblock copolymer was removed, along with the nitrogen attached to it by high-temperature calcination, so that porous carbon nitride nanosheets (Nv-CNN) with nitrogen vacancies were prepared. It was found that the presence of N vacancies promoted the separation of electron-hole pairs and the adsorption of O 2. The optimal photocatalytic H 2 O 2 production rate of Nv–CNN–3 could reach 1768 μmol h −1 g −1, which was 44.6 times higher than bulk C 3 N 4 (39.6 μmol h −1 g −1 ). This work might shed light on an in-depth understanding of the role of vacancy in photocatalytic H 2 O 2 production.