C-F bond integration in polymeric carbon nitride enables oxygen-tolerant photocatalytic reduction of NO to N₂.

Abstract

The selective photocatalytic decomposition of NO under oxygen-rich conditions presents a significant challenge, largely due to the preferential reduction of O₂ over NO. To overcome this limitation, we develop an F-modified polymeric carbon nitride catalyst (e-FCN). Under visible light irradiation in simulated ambient air (20% O₂), the e-FCN catalyst achieves 85% NO conversion with 92% selectivity toward N₂. It exhibits high apparent quantum yields for N₂ formation (29.1% at 365 nm and ≥ 9.9% between 405 and 465 nm) and maintains its performance over 12 consecutive cycles without deactivation. Mechanistic investigations indicate that the incorporation of a C-F bond suppresses the detrimental C=O formation from O₂ activation, thereby passivating the catalyst toward O₂. Concurrently, e-FCN selectively adsorbs NO and promotes N-N coupling between adjacent NO molecules, ultimately converting NO to N₂ via an N₂O intermediate. This synergy of selective NO adsorption and controlled decomposition enables selective and oxygen-tolerant photocatalytic NO decomposition.