SO_4^(2_)表面修饰对TiO_2结构及其光催化性能的影响

Effect of Sulfation on Structure and Photocatalytic Performance of TiO_2

采用溶胶-凝胶法制备了 TiO2和 /TiO2催化剂 .运用 XRD、 BET比表面测定、 IR和 DRS光谱等技术对催化剂进行了表征 ,并以光催化氧化分解溴代甲烷作为模型反应，考察了上述催化剂的光催化反应性能及其反应条件对光催化活性的影响 .结果表明 ,表面修饰使得催化剂的结构和光催化性能显著改善 ,催化剂表面形成具有超强酸性质的 L酸和 B酸协同中心 .与 TiO2相比 ,/TiO2光催化剂的锐钛矿含量高、晶粒小、 BET比表面积大、孔径分布集中、光谱吸收边蓝移 ,具有优异的光催化氧化活性、稳定性及抗湿性能 .

TiO2 and /TiO2 photocatalysts were prepared by sol- gel method and characterized by X- ray diffraction (XRD),BET N2 sorption analysis, IR spectroscopy and UV- Vis Diffuse Reflectance Spectroscopy (DRS).Photocatalytic degradation of CH3Br in air stream was studied over TiO2 and /TiO2 catalysts under various reaction conditions.The results indicated that the structural and photocatalytic properties of TiO2 were greatly improved by sulfation.The sulfated TiO2 (/TiO2) showed excellent reaction activity and stability for CH3Br photocatalytic decomposition even under the moist reaction conditions.It was found that both B acid sites and L acid sites exist on the /TiO2 catalyst,forming cooperative centers with superacidic characteristics.When compared to unmodified TiO2,the /TiO2 catalyst exhibited higher anatase content,smaller crystal size,higher specific surface area,centralized pore size distribution,and the blue- shifted band edge of Uv- vis adsorption spectra.