A structural defect strategy for NH2-UiO-66(Zr) to enhance photocatalytic NO removal activity and synchronously inhibit NO2

Photocatalysis technology is a promising method for air pollution control, but its further application is limited by low charge separation efficiency and poor conductivity. In this paper, the optical properties of NH2-UiO-66 are modified by a ligand defect strategy to enhance the photocatalytic oxidation of NO under visible light. The existence of defects has been confirmed through XPS, BET, and TGA characterization analysis. Meanwhile, the UV-Vis, photoluminescence (PL), and photoelectrochemical analysis demonstrate that the charge separation efficiency and electrical conductivity of the medium-structured defective sample (NU-66-80) have been significantly enhanced. Furthermore, in the photocatalytic NO removal experiment, the optimal sample (NU-66-80) exhibited a NO removal rate of 51.12 %, which is 2.91 times that of the pristine sample, and the conversion rate of NO to NO2-/NO3- is comparable to the removal rate, effectively inhibiting the generation of toxic by-products (NO2). Finally, ESR and in situ FT-IR are combined to explore the transformation path of NO, in which active substances (ROS) are the key to the transformation of NO into low-toxicity products. This study will provide an interesting strategy for constructing defects in MOFs photocatalysts to solve typical air pollution problems.