Effect of Designed Zr/Ti Molar Ratio on the Photocatalytic Activity of Sr-Zr-Ti Mixed Oxide Catalysts under Visible Light
Effect of Designed Zr/Ti Molar Ratio on the Photocatalytic Activity of Sr-Zr-Ti Mixed Oxide Catalysts under Visible Light
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设计Zr/Ti摩尔比对Sr-Zr-Ti混合氧化物催化剂可见光光催化活性的影响
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发表时间：
2013
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通讯作者：
Pan Lie-Qun
中科院分区：
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作者：
Huang Hai-Feng;Jia Jian-Ming;Lu Han-Feng;Zhang Hong-Hua;Pan Lie-Qun
采用分步沉淀法制备了一系列Sr-Zr-Ti（SZT）复合氧化物催化剂。采用X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和紫外-可见漫反射吸收光谱（UV-Vis）对催化剂进行了表征。研究了该催化剂对亚甲基蓝的光催化降解性能。结果表明，当Zr/Ti比为1时，SZT复合氧化物催化剂的光催化活性提高。这是由于晶格缺陷产生的活性光催化位点，因为Zr 4+掺杂。当Zr/Ti比≥1时，由于SrZrO 3和TinO 2n-1（n=4，9）新晶相的出现，促进了电子/空穴的分裂和传导，催化剂的光催化活性显著提高。典型的SZT样品（Zr/Ti=4）表现出最高的光催化活性，其一级反应速率常数是SrTiO 3样品的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 ratio1, the SZT mixed oxide catalysts showed improved photocatalytic activity. This was attributed to lattice defects creating active photocatalytic sites because of Zr 4+ doping. For Zr/Ti ratios≥1, the catalysts showed markedly improved photocatalytic activity because of new crystalline phases of SrZrO 3 and Ti n O 2n-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 3 sample.