介孔SO42-/TiO2的一步法制备及其光催化性能

通过对TiOSO4溶液热水解用一步法制备出大比表面积、高活性的介孔SO42-/TiO2光催化剂.用低温氮吸附-脱附等温线、XRD、Hammett指示剂、艾氏卡等方法对SO42-/TiO2催化剂进行了表征,以亚甲基蓝的光催化氧化降解反应考察了催化剂的光催化性能.结果表明,在焙烧过程中硫酸根和偏钛酸孔壁上的自由羟基键合,不仅有效地抑制了TiO2晶粒的长大和晶相转变,而且起到了孔结构形成的导向及支撑作用,使TiO2保持了介孔结构、较高的比表面积和锐钛矿相,同时S=O键的强电子诱导效应还使邻近的Ti成为超强酸中心,促进了TiO2光生电子-空穴对的分离,延长了电子-空穴对的寿命,从而有效地提高了TiO2的光催化活性.

One-step preparation and photocatalytic performance for mesoporous SO42-/TiO2

The mesoporous SO4^2-/TiO2 photocatalyst with a high specific surface area and high catalytic activity was prepared by one-step via thermal hydrolysis of TiOSO4. The catalyst was characterized by means of N2 adsorption-desorption isotherms, X-ray diffraction, Hammett indicator and Eschka. The photocatalytic performance was examined by the photocatalytic degradation reaction of methylene blue. The results show that the adsorbed SO4^2- links with free OH on the pore wall of metatitanic acid in roasting stage, which resists to grain growth and transformation of TiO2, and maintains the mesoporous structure as well as the high specific area of carrier TiO2. Furthermore, the strong electron inducement effect from S=O bond makes the adjacent Ti atom as a superacidic core, which accelerates the separation of photogenic electron-hole pair and prolongs its life-span, and improves the photocatalytic performance of TiO2.