The lead-free halide perovskite/UiO-66 with dual Lewis acid sites for efficient photocatalytic NO removal

Photocatalysis is a promising technology for removing low concentrations of nitric oxide (NO) from the atmosphere. However, the unsatisfactory photocatalytic NO removal efficiency and the high selectivity for NO 2 in catalysts limit the development of this technology. In this work, we used an in-situ synthesis method to incorporate Cs 3 Bi 2 Br 9 into UiO-66 for efficient and robust photocatalytic NO removal. The Cs 3 Bi 2 Br 9 /UiO-66 catalyst exhibits a 77.6 % NO removal efficiency and low NO 2 selectivity under visible light irradiation at a WHSV of 1,650,000 mL h −1  g −1 , exceeding the efficiencies of Cs 3 Bi 2 Br 9 (36.4 %) and UiO-66 (2.3 %), as well as those of most reported MOF-based photocatalysts. The synergy of weak Lewis acid sites from Cs 3 Bi 2 Br 9 in Cs 3 Bi 2 Br 9 /UiO-66 and the strong Lewis acid sites from UiO-66 promotes the enrichment of NO on the catalyst surface and act as electron traps to induce carrier separation, thereby promoting the generation of O 2 − to achieve high efficiency. This work provides a new idea for the development of catalysts in NO elimination.