Preparation of Ag/UiO-66-NH2 and its application in photocatalytic reduction of Cr(VI) under visible light

Herein, UiO-66-NH2 as a kind of metal organic framework materials (MOFs) is first prepared via a facile solvothermal method and then loaded with Ag nanoparticles to form an Ag/UiO-66-NH2 composite, which is applied as the photocatalyst for the visible-light driven reduction of Cr(VI). The UV-Vis diffuse reflectance spectroscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and photocurrent response analyses are performed to systematically characterize the composite. Ag nanoparticles with an average size of ca. 11.5 nm are distributed on the surface of UiO-66-NH2. The composite shows improved visible-light absorption ability and enhanced separation efficiency of photo-generated charge carriers. As a result, better photocatalytic Cr(VI) reduction is achieved on Ag/UiO-66-NH2 under the visible-light irradiation compared with UiO-66-NH2.