Effect of TiO doping modification on structure and catalytic performance of UiO-66

In order to obtain a highly active photocatalyst with visible light response, UiO-66 was modified by doping TiO and TiO@UiO-66 was synthesized with the hydrothermal method. Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and N adsorption-desorption were used to investigate the effect of TiO 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 m/g before modification, and the specific surface area of TiO@UiO-66 was similar to that of UiO-66 with a small amount of TiO doping. When the doping amount was increased to 15 mmol, the specific surface area of TiO@UiO-66 was decreased sharply to 413 m/g, since excessive TiO 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 TiO@UiO-66 reached 64.86%,which was 1.28 times that of UiO-66, when TiO doping amount was 10 mmol and visible light irradiation was 120 min. Therefore, appropriate TiO 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.