镍、硫共掺杂纳米TiO_2的制备及其可见光催化性能

Preparation of Ni/S/TiO_2 nanocomposition photocatalyst and photocatalysis under visible irradiation

为提高纳米TiO2的可见光催化活性,采用沉淀-浸渍法制备了一种新型Ni和S共掺杂TiO2纳米复合光催化剂.通过紫外-可见(UV-Vis-)漫反射、X-射线衍射(XRD)、透射电子显微镜(TEM)和X-荧光(EDX)等手段对其结晶形态、晶粒尺寸、元素掺杂量和吸光性能等进行了表征.结果显示,催化剂Ni/S/TiO2为锐钛矿晶相,平均粒径约为6～7nm,比表面积高达260.42m2/g,感光范围可拓展到可见光区,且与纯TiO2,S掺杂TiO2和Ni掺杂TiO2相比,光催化剂Ni/S/TiO2的颗粒粒径更小,比表面积更大,光吸收边红移程度更显著.以活性艳蓝198染料溶液为模拟废水,以氙光灯为光源,对光催化剂Ni/S/TiO2的催化活性进行了评价.结果表明,Ni/S/TiO2具有比纯TiO2、S掺杂TiO2和Ni掺杂TiO2更高的可见光催化活性,氙光灯照射120min,活性艳蓝198降解率可达到98.5%.

In order to improve visible light photocatalytic activities of nanometer TiO2,a novel Ni/S/TiO2 nanocomposition photocatalyst was prepared by precipitation-doping method. The optical characteristics,crystal and particle size of Ni/S/TiO2 photocatalyst were characterized by UV-Vis diffuse reflection spectra （DRS）,X-ray diffraction （XRD）,transmission electron microscopy （TEM） and energy dispersive X-ray fluorescence （（DX）. Results indicate that the Ni/S/TiO2 photocatalyst is anatase phase,its particle size is about 6～7 nm,its specific surface area is about 260.42 m2/g,and its absorption edge shifts to the visible light region. Compared with pure TiO2,S-doped TiO2 and Ni-doped TiO2,the sizes of Ni/S/TiO2 are smaller,its specific surface area is larger,and its absorption edge shifts more remarkably toward longer wavelength. The photocatalytic activities of Ni/S/TiO2 were evaluated using the photodegradation of reactive blue 198 as probe reaction under the irradiation of xenon light. The Ni/S/TiO2 photocatalyst shows higher photocatalytic activity than pure TiO2,S-doped TiO2 and Ni-doped TiO2. The degradation rate of reactive blue 198 reaches 98.5% under the irradiation of Xe light lamp for 120 min.