4-Aminobenzonitrile grafted carbon nitrides containing electron-deficient and −sufficient moieties for high-performance photosynthesis of hydrogen peroxide

The inherent electron-hole recombination, low light-absorption capacity and poor selectivity of photocatalysts hinder the production efficiency of hydrogen peroxide (H 2 O 2 ), necessitating the development of a catalyst with high catalytic activity. In this study, a supramolecular self-assembly method was employed to prepare 4-aminobenzonitrile-modified carbon nitride (Abz-CN). The incorporation of the cyano group rendered the charge distribution of Abz-CN inhomogeneous, leading to an increased dipole moment. This enhancement facilitated the separation and migration of photoinduced carriers. Additionally, density functional theory   (DFT) calculations revealed that Abz-CN had a higher propensity for oxygen adsorption and the formation of *OOH intermediates compared to carbon nitride (BCN). The H 2 O 2 generation rate of Abz-CN reached 3866 μmol·g −1 ·h −1 (under a 180 W xenon lamp, λ > 400 nm), which was 5.2 times that of BCN. Furthermore, the mechanism of Abz-CN followed a sequential two-step single-electron oxygen reduction process. This study showcases an innovative approach for bolstering the efficiency of photocatalytic H 2 O 2 generation.