C-TiO_2的制备及其对三氯乙酸的光催化降解

通过缓慢氧化T iC合成了C掺杂的锐钛矿型T iO2(C-T iO2)催化剂,并采用BET液氮吸附、X射线衍射、扫描电镜和紫外-可见吸收光谱对C-T iO2催化剂的比表面积、物相、粒径和吸收波长阀值等结构性质进行了表征。以难降解的三氯乙酸为催化降解对象,测定了C-T iO2催化剂在可见光照射下的催化活性。实验结果表明,相对于锐钛矿型T iO2,C-T iO2的吸收边带发生了约36nm的红移,它在可见光照射下有催化活性,主要是因为C取代O后,C的p轨道与O的2p轨道杂化,使其禁带隙变窄;制备条件和反应溶液的pH影响C-TiO2催化剂的活性,在350℃焙烧8h制备的C-TiO2催化剂,当反应溶液的pH为9时,催化活性最高。

Preparation of C-TiO2 and Its Photocatalysis in Degradation of Acetocaustin

Anatase TiO_2 doped with carbon(C-TiO_2)was prepared by mild oxidation of TiC in air.The prepared power was used as catalyst for photo-degradation of acetocaustin and was characterized by means of X-ray diffraction(XRD),scanning electron microscopy(SEM),UV-visible(UV-Vis)absorption spectroscopy and BET adsorption.Photocatalytic activity of catalyst was evaluated by photo-degradation of acetocaustin(TCA)under visible light.Relatively to anatase TiO_2,C-TiO_2 showed 36nm red shift in absorption sideband.Compared with nanocrystalline anatase TiO_2,the C-TiO_2 powder exhibited photoactivity for TCA degradation under visible light.When TiO_2 was doped with C,p orbits of C atoms mixed with 2p orbits of O atoms to narrow the band-gap,which could response to visible light.The highest photo-degradation activity for TCA could be reached under the conditions:C-TiO_2 prepared at 350℃ for 8h and pH of reaction solution 9.