The Direct Air Synthesis of Hydrogen Peroxide Induced by The Giant Built‐In Electric Field of Trz‐CN

Graphitic carbon nitride (C 3 N 4 ) has been identified as an optimal material for hydrogen peroxide (H 2 O 2 ) photosynthesis, although its utility is hampered by a high photocarrier recombination rate. Herein, a novel carbon nitride material with a giant built‐in electric field (BEF), Trz‐CN, is synthesized through a hydrothermal‐calcination tandem strategy. The giant BEF (4.8‐fold) induced by the large dipole moment facilitated the efficient separation and directional migration of photogenerated carriers. Trz‐CN exhibited an H 2 O 2 production rate of 569.9 µmol·g −1 ·h −1 using O 2 as feedstock under visible light ( λ > 420 nm), marking an impressive 11.2‐fold enhancement compared to bulk C 3 N 4 . Utilizing air instead of pure O 2 as feedstock resulted in a trivial 1.6% decrease in the H 2 O 2 generation by Trz‐CN while maintaining a substantial production rate of 560.6 µmol·g −1 ·h −1 . Notably, Trz‐CN showcased a sterilization rate of 99.9% against Escherichia coli (E. coli) in natural seawater. Density functional theory (DFT) calculations revealed that incorporating a nitrogen‐rich skeleton into the C 3 N 4 enhanced its oxygen adsorption capacity and lowered the energy barrier for H 2 O 2 formation. This leads to enhanced photocatalytic performance for H 2 O 2 generation under ambient air conditions. Trz‐CN provides a new exploratory idea for direct air synthesis of H 2 O 2 and ballast water treatment.