Effect of TiO<sub>2</sub> doping modification on structure and catalytic performance of UiO-66

Abstract

In order to obtain a highly active photocatalyst with visible light response, UiO-66 was modified by doping TiO₂ and TiO₂@UiO-66 was synthesized with the hydrothermal method. Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and <italic>N</italic>₂ adsorption-desorption were used to investigate the effect of TiO₂ doping on the structure and surface morphology of UiO-66. The results showed that all the samples had regular octahedral structure. The specific surface area of UiO-66 was high up to 1 270 m²/g before modification, and the specific surface area of TiO₂@UiO-66 was similar to that of UiO-66 with a small amount of TiO₂ doping. When the doping amount was increased to 15 mmol, the specific surface area of TiO₂@UiO-66 was decreased sharply to 413 m²/g, since excessive TiO₂ doping reduced the specific surface area of UiO-66. Removal of ceftriaxone sodium by samples under visible light was used as probe reaction to investigate its catalytic activity. The photocatalytic results showed that the removal rate of ceftriaxone sodium by TiO₂@UiO-66 reached 64.86%,which was 1.28 times that of UiO-66, when TiO₂ doping amount was 10 mmol and visible light irradiation was 120 min. Therefore, appropriate TiO₂ doping can improve the removal rate of UiO-66 to ceftriaxone sodium. This work may provide new insights into the design of modified UiO-66 photocatalyst and the photocatalytic degradation of cephalosporins.