Photocatalytic activity of rutile-anatase coupled TiO2 particles prepared by a dissolution-reprecipitation method.
Photocatalytic activity of rutile-anatase coupled TiO2 particles prepared by a dissolution-reprecipitation method.
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DOI：
10.1016/s0021-9797(03)00755-0
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发表时间：
2003-11
影响因子：
9.9
通讯作者：
T. Kawahara;Toshiaki Ozawa;Mitsunobu Iwasaki;H. Tada;S. Ito
中科院分区：
文献类型：
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作者：
T. Kawahara;Toshiaki Ozawa;Mitsunobu Iwasaki;H. Tada;S. Ito
将金红石TiO2颗粒部分溶解到H2SO4水溶液中，并通过添加NH3aq使Ti4+离子再沉淀。通过加热悬浮液离心后回收的固体来制备金红石-锐钛矿偶联的 TiO2 颗粒。通过改变金红石的溶解量可以任意控制锐钛矿的含量（cA，wt%）。评价了乙醛气相氧化的光催化活性。一阶速率常数 k 强烈依赖于 cA 和加热温度 (Tc)，随着 Tcat Tc⩽800°C 的增加而增加。在 Tc=800°C 下制备的 cA=0.5 wt% 的样品表现出比纯金红石 (k=0.08 h−1m−2) 和锐钛矿 (k=0.34 h−1m−2) 更高的活性水平 (k=0.94 h−1m−2)。这种显着的增强效果主要是通过光诱导从锐钛矿到金红石的界面电子转移来解释的。
Rutile TiO2particles were partly dissolved into aqueous solutions of H2SO4, and the Ti4+ions were reprecipitated by adding NH3aq. Rutile–anatase coupled TiO2particles were prepared by heating the solid recovered after centrifugation of the suspension. The content of anatase (cA, wt%) could be controlled arbitrarily by changing the dissolved amount of rutile. The photocatalytic activity for the gas-phase oxidation of acetaldehyde was evaluated. The first-order rate constant, k, strongly depended on both cAand heating temperature (Tc), increasing with an increase in Tcat Tc⩽800°C. The sample with cA=0.5 wt% prepared at Tc=800°C exhibited a much higher level of activity (k=0.94 h−1m−2) than those of pure rutile (k=0.08 h−1m−2) and anatase (k=0.34 h−1m−2). This remarkable enhancing effect was explained mainly in terms of photoinduced interfacial electron transfer from anatase to rutile.