Sol-gel prepared InTaO_4 and its photocatalytic characteristics
Sol-gel prepared InTaO_4 and its photocatalytic characteristics
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DOI：
10.1557/jmr.2008.0172
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发表时间：
2008-05
影响因子：
2.7
通讯作者：
Hsian Chen;Hung-Chi Chou;J. Wu;Hsin-yu Lin
中科院分区：
文献类型：
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作者：
Hsian Chen;Hung-Chi Chou;J. Wu;Hsin-yu Lin
InTaO_4是一种高效的可见光光催化剂，以往的合成方法是在1100 °C以上的温度下进行固相熔融。但由于固体前驱体熔融不均匀，导致颗粒形貌不规则，团聚严重。本研究采用两种溶胶-凝胶法，即热水解法和酯化法合成了InTaO_4。前驱体为五水硝酸铟[In（NO_3）_3]和丁醇钽[Ta（OC_4 H_9）_5]。采用酯化法在950 °C下成功地合成了平均粒径为17.7 nm的InTaO_4粉体。用酯化法制备的溶胶在1100 °C下在光纤上形成了厚度近40 nm的均匀InTaO_4薄膜。首次以可见光照射下水溶液中CO_2光还原反应为指标，对InTaO_4的光催化活性进行了评价。在InTaO_4表面负载助催化剂NiO，进一步提高了甲醇的产率。酯化法制备的NiO/InTaO_4的甲醇产率明显高于固相熔融法制备的NiO/InTaO_4。酯化法使Ta（OC_4H_9）_5和In（NO_3）_3混合均匀，得到结晶均匀、上级光催化活性高的纳米InTaO_4。
InTaO_4 is an efficient visible-light photocatalyst, which used to be synthesized by solid-state fusion at over 1100 °C. However, irregular morphology and severe agglomeration of particles were acquired due to nonuniform fusion of solid precursors. In this study, InTaO_4 was synthesized by two sol-gel routes, the thermal hydrolysis and esterification methods. The precursors were indium (III) nitrate pentahydrate [In(NO_3)_3] and tantalum(V) butoxide [Ta(OC_4H_9)_5] dissolved in solutions. The InTaO_4 powders with a uniform grain size of 17.7 nm were successfully synthesized using the esterification method at a calcination temperature of 950 °C. A uniform InTaO_4 thin film nearly 40 nm thick formed on an optical fiber at 1100 °C using the sol prepared by the esterification method. For the first time, InTaO_4 was evaluated by the photocatalytic activity of CO_2 photo reduction, which was conducted in aqueous solution under visible light irradiation. Cocatalyst NiO was loaded on the surface of InTaO_4 to further enhance the methanol yield. The methanol yields of NiO/InTaO_4 by esterification method were significantly higher than those by solid-state fusion. The esterification method provided homogeneous mixing of Ta(OC_4H_9)_5 and In(NO_3)_3, resulting in nano-sized InTaO_4 with uniform crystallinity and superior photocatalytic activity.