Synergically integrating carbon-vacancy defected carbon nitride with anthraquinone for boosted photocatalytic H₂O₂...

Carbon nitrides (CN) have been extensively studied in hydrogen peroxide (H₂O₂) photosynthesis research field owing to their remarkable stability and tunable structural properties. Nevertheless, the weak photogenerated carrier separation ability, the insufficient adsorption and activation of O₂, and the high reduction potential for H₂O₂ generation on CN limit their applications in photocatalytic H₂O₂ production. Herein, we successfully prepared all-organic CN-based photocatalysts (AQ/CvCN) via combining CN with carbon vacancies (Cv) and anthraquinone (AQ) to overcome the above limitations, thereby enhancing photocatalytic H₂O₂ production. Significantly, experimental results and theoretical calculations demonstrate that the introduced Cv can break the symmetrical structure of CN and act as electron capture sites, which remarkably enhances the photogenerated carrier separation and the adsorption and activation of O₂, while the loading of AQ can optimize the reduction potential of O₂ to H₂O₂ and reduce the formation energy barrier of the critical intermediate *OOH, therefore collaboratively improving the activity of photocatalytic H₂O₂ production. The designed 20% AQ/CvCN catalyst achieved a photocatalytic H₂O₂ production rate of 10,053.46 μmol g^-1 h^-1, which is 18.16 and 5.58 times higher than that of CN and CvCN, respectively. In addition, 20% AQ/CvCN maintains stable H₂O₂ evolution activity after long-term cycling tests. This study provides an efficient, economical, and environmentally friendly approach for designing CN-based photocatalysts used in photocatalytic H₂O₂ production.