Surface charge transfer adjustment from designing thin-layer structure targeted O2 adsorption and activation for deep NO oxidation on Bi2MoO6

Photocatalytic oxidation of nitrogen oxides (NO x ) is a promising technology for environmental protection and green sustainable development. However, its practical application remains limited due to inefficient activation of NO and O 2 , stemming from inadequate structural design of photocatalysts. Herein, we developed a thin-layer two-dimensional (2D) material Bi 2 MoO 6 (BMO) via cetyl trimethyl ammonium chloride (CTAC) addition in synthesis process, which effectively modulates the surface electronic structure, enhance the light absorption and activation of NO and O 2 . This thin-layer Bi 2 MoO 6 nanosheets achieved a NO oxidation efficiency of 45.3 ​%, which was about 5.5 times that of traditional bulk BMO (8.2 ​%). Additionally, it demonstrated superior selectivity for NO 2 − /NO 3 − production (86.6 ​%) compared to bulk BMO (60.5 ​%) and significantly reduced the formation of toxic NO 2 byproducts (13.4 ​% vs. 39.5 ​%). Combining experimental characterizations and density functional theory (DFT) simulations, it demonstrated that the electron-hole pair separation could be promoted and targeted adsorption activation of O 2 can be enhanced to form superoxide radicals (•O 2 − ) and singlet oxygen ( 1 O 2 ) via the effect of surface charge transfer adjustment on the thin-layer structure of Bi 2 MoO 6 , which are key factors affecting the efficiency and selectivity of photocatalytic oxidation of NO. This work provides important insights into the formation of directed ROS and proposes a unique mechanism for selective NO oxidation.