摘要
通过分步沉积法制备了不同Zr/Ti摩尔比的锶锆钛(SZT)复合氧化物催化剂, 以X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、紫外-可见(UV-Vis)漫反射光谱等表征手段考察不同Zr/Ti摩尔比下SZT催化剂的结构形态, 以可见光下光催化降解亚甲基蓝为模型反应考察样品的光催化活性. 结果表明: Zr/Ti摩尔比<1时SZT 催化剂发生 Zr4+与Ti4+同质替换, 引起晶格缺陷, 光催化活性小幅提高; Zr/Ti摩尔比≥1时SZT催化剂产生SrZrO3/TinO2n-1(n=4, 9)的新晶相, TinO2n-1(n=4, 9)的存在有利于光生电子-空穴的传导与分离, 可大幅提高催化剂光催化活性. 其中, SZT-5/5表现出最高的光催化活性, 其一级反应速率常数达到0.2133 min-1, 是同等光照条件下纯SrTiO3样品(0.0158 min-1)的 13.5 倍.
A series of Sr-Zr-Ti （SZT） mixed oxide catalysts were prepared by a fractional-precipitation method. These photocatalysts were characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM）, transmission electron microscope （TEM）, and ultraviolet visible （UV-Vis） diffuse reflectance absorption spectra. Photocatalytic degradation of methylene blue was investigated to determine the photoactivity of the catalyst. It was shown that with a Zr/Ti ratio〈l, the SZT mixed oxide catalysts showed improved photocatalytic activity. This was attributed to lattice defects creating active photocatalytic sites because of Zr4＋ doping. For Zr/Ti ratios〉l, the catalysts showed markedly improved photocatalytJc activity because of new crystalline phases of SrZrO3 and TinO2n-1 （n=4, 9） that facilitated splitting and conduction for electron/hole. Typical SZT samples （Zr/Ti=4） showed the highest photocatalytic activity, with first-order reaction rate constant 13.5 times that of a SrTiO~ sample.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2013年第6期1319-1326,共8页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(21107096)资助项目~~
