Double-Beam Photoacoustic Spectroscopic Studies on Transient Absorption of Titanium(IV) Oxide Photocatalyst Powders
Double-Beam Photoacoustic Spectroscopic Studies on Transient Absorption of Titanium(IV) Oxide Photocatalyst Powders
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DOI：
10.1021/jp071362x
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发表时间：
2007-07
影响因子：
3.7
通讯作者：
N. Murakami;O. O. P. Mahaney-O.;R. Abe;T. Torimoto;B. Ohtani
中科院分区：
文献类型：
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作者：
N. Murakami;O. O. P. Mahaney-O.;R. Abe;T. Torimoto;B. Ohtani
采用双束光声（PA）光谱研究了连续紫外照射下氧化钛（IV）氧化物（TiO2）粉末的原位光吸收性能。这种 PA 测量能够观察到各种 TiO2 粉末样品上出现的两种紫外线诱导的中间物质。大多数样品（类型1）由于三价钛（Ti3+）物质的产生而表现出光吸收，而具有相对较大比表面积的锐钛矿样品（类型2）也观察到归因于捕获空穴或表面过氧物质的瞬态吸收。光诱导 Ti3+ 物质的时间分辨测量和动力学分析表明，与 1 型样品相比，2 型样品中积累的电子对分子氧具有较高的反应性。对于两种类型的样品，在表面吸附甲醇存在的情况下，在脱气条件下归因于 Ti3+ 物质的 PA 信号强度的饱和极限进行了估计，...
In situ photoabsorption properties of titanium(IV) oxide (TiO2) powders under continuous ultraviolet irradiation were investigated by double-beam photoacoustic (PA) spectroscopy. This PA measurement enabled observation of two kinds of ultraviolet-light-induced intermediate species appearing on various kinds of TiO2 powder samples. Most of the samples (type 1) exhibited photoabsorption due to the production of trivalent titanium (Ti3+) species, while transient absorption assigned to trapped holes or surface peroxy species was also observed for anatase samples with a relatively large specific surface area (type 2). Time-resolved measurements and analyses of the kinetics of photoinduced Ti3+ species suggest that electrons accumulated in type-2 samples have high reactivity toward molecular oxygen compared to type-1 samples. Saturation limits of intensity of the PA signal attributed to Ti3+ species under deaerated conditions in the presence of surface-adsorbed methanol were estimated for both types of samples,...