From structure to function: Mechanistic exploration of calcium and strontium in carbon-doped boron nitride for enhanced nitric oxide oxidation

Heterogeneous photocatalysis rarely employs main group metals as active centers due to the lack of available d orbitals. In this study, alkaline earth metal centers were introduced into a carbon-doped boron nitride framework, leading to an optimization of their electronic structure and successful activation of catalytic activity. Interestingly, these metal centers were found to effectively utilize d orbitals or d/p hybrid orbitals to activate O 2 and H 2 O, thereby generating a wealth of reactive oxygen species (ROS), which efficiently convert NO to NO 3 - . In addition, the optimized alkaline earth metal structural unit can not only strengthen carrier separation, but also improve the adsorption behavior of NO 2 on the catalyst surface and promote its further conversion to NO 3 - . This research provides new insights into the design of highly active sites and the exploration of catalytic mechanisms for alkaline earth metals.