Preparation And Properties Of Tantalate Photocatalysts

In this paper,non-mentallic doping sodium tantalate and non-mentallic doping potassium tantalate photocatalyst were prepared by a variety of methods.The composition,morphology,and surface atomic state of the samples were analysis by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),high resolution transmission electron microscopy(HRTEM),selective electron diffraction(SAED),X-ray photoelectron spectroscopy(XPS)and so on.Finally,the prepared samples were tested for photocatalytic performance and their absorbance was characterized by UV-Vis spectrophotometer.(1)Sulfur-doped sodium tantalate was prepared in one step by hydrothermal method,and TaCl5 as tantalum source and Na2S2O3·5H2O as sulfur source.SEM and TEM results showed that the particle size distribution is from 200 nm to 1 ?m.XRD results showed that sodium tantalate can not be formed at 140 ?C,and sodium tantalate with better crystal form can be formed at 180 ?C.XPS results showed that the doped S ions replace the O ions,so that the band gap of tantalate is reduced.The photocatalytic test showed that sulfur doping sodium tantalate had good catalytic degradation effect on Rhodamine B under visible light.(2)The carbon-doped sodium tantalate was prepared by solvothermal method,the mixed solution of water and ethylene glycol as solvent.SEM results showed that the sample was cube,the particle size distribution is about 1 ?m.The XRD results showed that the crystal phase of sodium tantalate is NaTaO3.The higher is the concentration of ethylene glycol in the solution,the worse is the crystallinity of the product.Photocatalytic experiments showed that too much or too little ethylene glycol in the solvent will reduce the photocatalytic performance of the sample.(3)Nitrogen-doped potassium tantalate was prepared by two-step hydrothermal method.The N-Ta2O5 precursor was prepared by sintering in NH3 atmosphere,then K2Ta2O6 was prepared by a hydrothermal method.The XRD results showed that the crystal phase of the sample is K2Ta2O6.SEM results showed that the size of K2Ta2O6 sample is about 100 nm.With the extension of the reaction time,the morphology of the sample grows from the particles to the positive octahedron and finally grows into cubic.The results of photocatalytic test showed that the photocatalytic activity of the samples was the best when the reaction time was 24 h and the reaction temperature was 180 ?C.