We report for the first time that NV-incorporated g-C₃N₄ can selectively photoreduce N₂ and is free from the interference of other gases.

Quantum dot (QD) sensitization can increase the light absorption and electronic transmission of photocatalysts. However, limited studies have been conducted on the photocatalytic activity of photocatalysts after modification by noble metal QDs. In this study, we developed a simple method for fabricating Pd-QD-modified g-C₃N₄. Results showed that the modification of Pd-QDs can improve the NO photocatalytic oxidation activity of g-C₃N₄. Moreover, Pd-QD modification changed the NO oxidation mechanism from the synergistic action of h⁺ and O₂⁻ to the single action of ·OH. We found that the main reason for the mechanism change was that Pd-QD modification changed the molecular oxygen activation pathway from single-electron reduction to two-electron reduction. This study can not only develop a novel strategy for modifying Pd-QDs on the surface of photocatalysts, but also provides insight into the relationship between Pd-QD modification and the NO photocatalytic oxidation activity of semiconductor photocatalysts.