Nitrogen vacancy-rich porous carbon nitride nanosheets for efficient photocatalytic H2O2 production

Photocatalytic production of H2O2 has attracted widespread attention as an environmental-friendly approach. However, the low activity and selectivity of photocatalytic H2O2 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 O2. The optimal photocatalytic H2O2 production rate of Nv–CNN–3 could reach 1768 μmol h−1g−1, which was 44.6 times higher than bulk C3N4 (39.6 μmol h−1g−1). This work might shed light on an in-depth understanding of the role of vacancy in photocatalytic H2O2 production.