Construction of Ag-NH2-UiO-66 composites with boosted photocatalytic activity for the removal of contaminants

The environmental pollution resulting from organic dye wastewater presents a significant threat to human health. Photocatalysis has emerged as a highly promising approach for mitigating wastewater contamination. In this study, a novel synthetic strategy was developed using NH 2 -UiO-66 as a template. By precisely controlling the amount of Ag + ions introduced into the NH 2 -UiO-66 precursor and employing a straightforward reduction approach, the Ag-NH 2 -UiO-66 composite photocatalyst was successfully synthesized. Comprehensive characterization via X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray photoelectron microscopy (XPS) confirmed that the incorporated Ag+ ions were effectively reduced to metallic silver and uniformly dispersed within the porous framework. Photocatalytic degradation experiments employing Rhodamine B (RhB) as a model pollutant under ultraviolet irradiation demonstrated that the catalyst with a silver loading of 0.05 mol/L achieved a maximum degradation efficiency of 91% within 150 min, markedly surpassing the 39% efficiency exhibited by pristine NH 2 -UiO-66. Furthermore, cyclic stability tests verified the catalyst's excellent reusability and structural durability. Mechanistic investigations revealed that superoxide radicals (O 2 − ) served as the predominant reactive species responsible for RhB degradation in the Ag-NH 2 -UiO-66 system. This work presents a simple and effective strategy for fabricating highly efficient and stable MOF-based photocatalysts for the remediation of dye-contaminated wastewater.