Effect of Photoexcited Electron Dynamics on Photocatalytic Efficiency of Bismuth Tungstate
Effect of Photoexcited Electron Dynamics on Photocatalytic Efficiency of Bismuth Tungstate
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DOI：
10.1021/jp2051257
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发表时间：
2011-07
影响因子：
3.7
通讯作者：
Fumiaki Amano;Akira Yamakata;Kohei Nogami;M. Osawa;B. Ohtani
中科院分区：
文献类型：
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作者：
Fumiaki Amano;Akira Yamakata;Kohei Nogami;M. Osawa;B. Ohtani
采用时间分辨红外吸收光谱研究了钨酸铋（Bi2WO6）光催化剂的光激发载流子动力学。中红外区域的单调吸收可归因于光激发电子的吸收，被监测为光激发后微秒至毫秒范围内的时间延迟的函数。采用水热法在不同温度下制备了不同晶型含量的Bi2WO6纳米粒子，并研究了光激发载流子密度与稳态光催化效率的关系。使用两个反应测试光催化效率：乙酸在水溶液中的氧化分解（反应1）和乙醛在空气中的氧化分解（反应2）。Bi2WO6颗粒的晶化抑制了光激发电子和空穴在1 μs内的快速复合。在结晶颗粒的情况下，光激发电子的密度随着温度的增加而增加。
Photoexcited carrier dynamics of bismuth tungstate (Bi2WO6) photocatalysts was investigated by time-resolved infrared (IR) absorption spectroscopy. Monotonic absorption at the mid-IR region, which is attributable to absorption by photoexcited electrons, was monitored as a function of time delay from the microsecond to millisecond range after photoexcitation. Bi2WO6 particles with different crystalline content were prepared by hydrothermal reaction at several temperatures and used to elucidate the relation between density of photoexcited carriers and steady-state photocatalytic efficiency. Photocatalytic efficiency was tested using two reactions: oxidative decomposition of acetic acid in an aqueous solution (reaction 1) and oxidative decomposition of acetaldehyde in air (reaction 2). Crystallization of Bi2WO6 particles suppressed the fast recombination of photoexcited electrons and holes within 1 μs. In the case of crystallized particles, the density of the photoexcited electron increased with an increase ...