Preparation And Studying Of Photocatalytic Property Of Layered Titanium-based Polyoxometalats

Titanium-based ployoxometalats are a typical cationic layered compounds. their physical and chemical properties can be changed for exchangeability of interlayer cation, and thus to improve the photocatalytic activity.In this paper. Layered titanium-based ployoxometalats K2Ti4O9and CsTi2NbO7were prepared by the high temperature solid state reaction. Transition metal oxide Fe2O3intercalated into layered titanium-based ployoxometalats by the modified technique of H+exchange and stripping-assembly. The structure、morphology and spectral response of catalysts as-prepared were characterized by means of power X-ray diffraction(XRD)、Scanning electron microscope(SEM)、Transmission electron microscope(TEM)、Ultraviolet visible diffused reflection (UV-vis DRS) and Fourier transform infrared(FT-IR) spectroscopy. The photocatalytic oxidation ability was evaluated qualitatively with ethanethiol as probes.The experimental result indicated that monoclinic K2Ti4O9and orthorhombic CsTi2NbO7had a good layered structure and their crystal forms were relative perfect. Intercalated products Fe2O3/H2Ti4O9and Fe2O3/HTi2NbO7were obtained by the method of stripping-assembling. The analysis results of XRD indicated that the interlamellar spacing of intercalated samples had increased. and FT-IR indicated that vibration absorption peaks of the sample’s framework were blue shift. UV-vis DRS indicated that the spectral response of the samples moved to the visible region and the band-gap energy had reduced. The whole results suggested that Fe2O3had consisted in the sample.The adsorptive capacity and photocatalytic oxidation ability of catalysts were evaluated by adsorbing ethanethiol in static state. The detention conditions of the reactants and oxidation products on the surface of the catalysts were measured by FT-IR. The results indicated that adsorption of ethanethiol was only physical adsorption on the surface of the precursor K2Ti4O9and CsTi2NbO7, and catalytic oxidation reaction didn’t act in natural light condition. Intercalated layered composite oxides samples had a good adsorptive capacity to ethanethiol, meanwhile the spectral response of the samples moved to the visible region and energy band had reduced. As a result the samples had a good photocatalytic oxidation and can make ethanethiol oxidation of the sulfonic acid and sulfonic acid esters.The layer structure of multilayer titanates and titanoniobates offered a good building block for building suitable photocatalytic materials. Composite photo-catalysts which were constructed by module assembly of metallic oxide intercalation possessed a good adsorption and photocatalytic oxidation ability.