Gd^(3+)-doped monodisperse TiO_2 hollow microspheres with various molar ratios of Gd^(3+)/TBOT were synthesized via a novel process, which involved the preparation of SiO_2 templates, deposition of Gd^(3+)-doped TiO_2...Gd^(3+)-doped monodisperse TiO_2 hollow microspheres with various molar ratios of Gd^(3+)/TBOT were synthesized via a novel process, which involved the preparation of SiO_2 templates, deposition of Gd^(3+)-doped TiO_2 by sol-gel, SiO_2 coating, heat treatment to induce crystallization of TiO_2, and finally etching away the inner SiO_2 templates and outer SiO_2 layers. The synthesized samples were characterized by transmission electron microscopy(TEM), scanning electron microscopy(SEM), X-ray diffraction(XRD), diffuse reflection spectroscopy(DRS), specific surface area measurement(BET) and X-ray photoelectron spectroscopy(XPS), respectively. The photocatalytic activity of Gd^(3+)-doped samples was evaluated via photocatalytic degradation of Methyl orange under UV irradiation. The results show that the SiO_2 layers prevent aggregation of TiO_2 hollow microspheresand improve the thermal stability of the synthesized samples. Also, the photocatalytic activity of monodisperse TiO_2 hollow microspheres can be enhanced at the optimal molar ration of Gd^(3+)/TBOT of 0.7%.展开更多
文摘Gd^(3+)-doped monodisperse TiO_2 hollow microspheres with various molar ratios of Gd^(3+)/TBOT were synthesized via a novel process, which involved the preparation of SiO_2 templates, deposition of Gd^(3+)-doped TiO_2 by sol-gel, SiO_2 coating, heat treatment to induce crystallization of TiO_2, and finally etching away the inner SiO_2 templates and outer SiO_2 layers. The synthesized samples were characterized by transmission electron microscopy(TEM), scanning electron microscopy(SEM), X-ray diffraction(XRD), diffuse reflection spectroscopy(DRS), specific surface area measurement(BET) and X-ray photoelectron spectroscopy(XPS), respectively. The photocatalytic activity of Gd^(3+)-doped samples was evaluated via photocatalytic degradation of Methyl orange under UV irradiation. The results show that the SiO_2 layers prevent aggregation of TiO_2 hollow microspheresand improve the thermal stability of the synthesized samples. Also, the photocatalytic activity of monodisperse TiO_2 hollow microspheres can be enhanced at the optimal molar ration of Gd^(3+)/TBOT of 0.7%.
