微米级大孔结构二氧化钛的光催化活性  

Photocatalytic Activity of TiO_2 with Micrometer-Sized Macropores

作　　者：佟欣[1] 陈睿[1] 陈铁红[1] 

机构地区：[1]南开大学化学学院新催化材料科学研究所,先进能源材料化学教育部重点实验室,天津300071

出　　处：《物理化学学报》2011年第8期1941-1946,共6页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(20873070,20973095)资助项目~~

摘　　要：以溶胶-凝胶法合成了具有微米级大孔孔道结构的锐钛矿晶型TiO2,以紫外光催化降解染料罗丹明B(RhB)考察了大孔结构材料的光催化活性.对比研磨粉碎后失去大孔结构的材料的光催化活性,我们发现在相同的实验条件下,大孔结构的TiO2并不具有更好的光催化效果,即对于本文所合成的大孔结构TiO2,单纯的微米级大孔的形貌对材料的光催化活性没有明显的促进作用,而更多的TiO2外表面受到紫外光照射是促进光催化效果的直接原因.由于研磨后样品颗粒尺寸不均匀,为了避免颗粒大小不均匀对光催化活性的影响,我们又用十六烷基三甲基溴化铵(CTAB)和聚丙烯酸(PAA)为模板合成了形貌均匀尺寸不同的微球,并证明了粒子尺寸越小催化效果越好.Macroporous TiO2 with aligned channels was synthesized using citric acid as a chelator. The wall of the macropore was composed of nanosized anatase crystals. The degradation of rhodamine B （RhB） was used as a model reaction to test the photocatalytic activity of the samples. Compared with ground TiO2 powder, macroporous TiO2 with aligned channels did not give a better photocatalytic RhB degradation property. Because of the scattering of UV-light by anatase nanoparticles, the TiO2 located inside the macroporous wall was not irradiated by UV-light, and this affected the photocatalytic property of the macroporous TiO2. The photocatalytic property improved upon exposing more of the external TiO2 surface to UV light. Furthermore, uniform and dispersed micrometer sized TiO2 spheres were fabricated using cetyltriethylammonium bromide （CTAB） and polyacrylic acid （PAA） as templates. The photocatalytic degradation of RhB confirmed that reducing the particle size improved the efficiency of the photocatalytic activity.

关 键 词：二氧化钛 光催化 形貌 大孔结构 散射 

分 类 号：O643.36[理学—物理化学]