Layered perovskite oxyhalides Bi 4 MO 8 X (M = Nb, Ta; X = Cl, Br) are promising visible-light photocatalysts for water splitting, where the polar structure may enhance the conductivity of photocarriers. In this study, the domain structure of Bi 4 NbO 8 Br single crystal was investigated using piezoresponse force microscopy and transmission electron microscope. We observed a rare domain structure with a ferroelectric 180° domain in the nanoscale ferroelastic 90° domains developed in the ab plane. We also discuss the effect of these domain structures on the dynamics of photocarriers, which may provide new ideas for the design of highly active photocatalyst.

中文翻译：

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具有层状钙钛矿结构的可见光光催化剂Bi 4 NbO 8 Br的畴观察

层状钙钛矿卤氧化物Bi 4 MO 8 X（M = Nb，Ta; X = Cl，Br）是用于水分解的有希望的可见光光催化剂，其中极性结构可增强光载体的导电性。在这项研究中，Bi 4 NbO 8 Br单晶的畴结构使用压电响应力显微镜和透射电子显微镜研究。我们观察到在ab平面上形成的纳米级铁弹性90°域中具有铁电180°域的稀有域结构。我们还讨论了这些域结构对光载流子动力学的影响，这可能为高活性光催化剂的设计提供新的思路。