Insights into the Role of Ferroelectric Polarization in Piezocatalysis of Nanocrystalline BaTiO3
Insights into the Role of Ferroelectric Polarization in Piezocatalysis of Nanocrystalline BaTiO3
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DOI：
10.1021/acsami.8b01991
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发表时间：
2018-05-30
影响因子：
9.5
通讯作者：
Bao, Dinghua
中科院分区：
文献类型：
--
作者：
Wu, Jiang;Xu, Qi;Bao, Dinghua
压电效应，通常称为压电/铁电材料在机械应力下的电极化变化，被广泛用作催化降解有机污染物的驱动力。然而，电极化和压电催化活性之间的关系仍然不清楚。在这项工作中，我们研究了BaTiO 3纳米粒子的压电催化活性的铁电极化的作用，通过退火BaTiO 3在不同的温度或极化BaTiO 3在不同的电场。在800 ℃退火的钛酸钡纳米粒子表现出有效增强的压电催化活性相比，在其他温度下退火。在较高温度下退火的多晶颗粒表现出大大降低的催化活性。极化后的多晶BaTiO_3颗粒的压催化活性明显提高。此外，我们确定了自由基物种和催化反应的中间产物。从理论上解释了BaTiO_3压电催化剂电极化与退火温度和超声振动的关系。我们的研究表明，增加铁电极化（而不是微晶尺寸）可以有效地提高压电催化活性。我们相信，目前的工作提供了一个清晰的理解，在压电催化的铁电极化的作用。
Piezoelectric effect, commonly known as a change in electric polarization in piezoelectric/ferroelectric materials under mechanical stress, is extensively employed as a driving force for the catalytic degradation of organic pollutants. 1 A However, the relationship between electric polarization and piezocatalytic activity is still unclear. In this work, we investigated the role of ferroelectric polarization in the piezocatalytic activity of BaTiO3 nanoparticles through annealing BaTiO3 at different temperatures or poling BaTiO3 at different electric fields. The BaTiO3 nanoparticles annealed at 800 degrees C exhibit effectively enhanced piezocatalytic activity compared with those annealed at other temperatures. The polycrystalline particles annealed at higher temperatures exhibit a greatly reduced catalytic activity. After poling, the piezocatalytic activity of the polycrystalline BaTiO3 particles was obviously improved. In addition, we identified the free radical species and the intermediate products of the catalytic reaction. We also well-explained the dependence of electric polarization in the BaTiO3 piezocatalyst on annealing temperature and ultrasonic vibration theoretically. Our study indicates that increasing ferroelectric polarization (but not crystallite size) can effectively enhance the piezocatalytic activity. We believe that the present work provides a clear understanding of the role of ferroelectric polarization in piezocatalysis.