Visible light-driven deep oxidation of NO and its durability over Fe doped BaSnO3: The NO+ intermediates mechanism and the storage capacity of Ba ions

A Fe doped BaSnO3 (Fe-BaSnO3) photocatalyst was synthesized by a decomposition method of the peroxo-precursor. The Fe-BaSnO3 not only exhibited a great activity and selectivity in NO photocatalytic oxidation under visible light but also showed an excellent performance in terms of durability. The experimental results showed that doping Fe ions into BaSnO3 produced more oxygen vacancies (OVs) and visible light further promoted the formation of OVs, which was beneficial to the formation of reactive oxygen species (ROS). The Fe ions benefited to convert NO to a high-energy NO+, which was easily deep-oxidized into nitrate. Moreover, the alkaline earth metal ions (Ba2+) could store the nitrate or nitrite generated by the NO oxidation, resulting in exposing the active sites at Fe ions and then maintaining the durable oxidizing NO over Fe-BaSnO3. This work may shed light on a novel strategy for developing high-efficiency photocatalysts for durable deep oxidation of NOx.