Reinforced ROS Generation and Anti‐Photocorrosion for Boosted Photooxidation Disinfection by IEF‐Enhanced Type II Charge Carrier Dynamics

ABSTRACT The internal electric field (IEF) is key in speeding up the separation and transfer of photogenerated carriers, which boosts the production of reactive oxygen species (ROS). In this study, we present a novel silver iodide/N‐rich carbon nitride (AgI/C 3 N 5 ) heterojunction catalyst with an IEF directed from AgI to C 3 N 5 . We confirmed this IEF using density functional theory (DFT) calculations and various characterization methods. This IEF induces and reinforces the Type II transfer pathway for carrier separation and transfer, significantly increasing the production of ROS, particularly singlet oxygen ( 1 O 2 ). As a result, the AgI/C 3 N 5 catalysts achieve 10.1 times the disinfection efficiency of C 3 N 5 and 5.6 times that of AgI, under one‐min reaction time, 10 7 CFU/mL of E. coli , visible light, and room temperature. It also outperforms most other AgI and carbon nitride‐based heterojunction photocatalysts. Notably, the photogenerated holes (h + ) selectively oxidize superoxide radicals (∙O 2 − ) to 1 O 2 due to favorable energy alignment, minimizing O 2 reduction effects and enhancing photocorrosion resistance, as demonstrated in five consecutive cycling experiments. In addition, the actual water disinfection tests confirmed its practical application potential. This work highlights the AgI/C 3 N 5 heterojunction catalyst's promise as an efficient disinfection agent and sheds light on the photocatalytic disinfection mechanism.