Nano‐Ferroelectric for High Efficiency Overall Water Splitting under Ultrasonic Vibration

作者：Ran Su, H. Alex Hsain, Ming Wu, Dawei Zhang, Xinghao Hu, Zhipeng Wang, Xiaojing Wang, Fa‐tang Li, Xuemin Chen, Li‐Na Zhu, Yong Yang, Yaodong Yang, Xiaojie Lou, Stephen J. Pennycook · 发表于：Angewandte Chemie · 年份：2019 · DOI：10.1002/ange.201907695 · 被引用次数：23 · 研究领域：Ferroelectric and Piezoelectric Materials、Electronic and Structural Properties of Oxides、Multiferroics and related materials

Abstract Piezocatalysis, converting mechanical vibration into chemical energy, has emerged as a promising candidate for water‐splitting technology. However, the efficiency of the hydrogen production is quite limited. We herein report well‐defined 10 nm BaTiO 3 nanoparticles (NPs) characterized by a large electro‐mechanical coefficient which induces a high piezoelectric effect. Atomic‐resolution high angle annular dark field scanning transmission electron microscopy (HAADF‐STEM) and scanning probe microscopy (SPM) suggests that piezoelectric BaTiO 3 NPs display a coexistence of multiple phases with low energy barriers and polarization anisotropy which results in a high electro‐mechanical coefficient. Landau free energy modeling also confirms that the greatly reduced polarization anisotropy facilitates polarization rotation. Employing the high piezoelectric properties of BaTiO 3 NPs, we demonstrate an overall water‐splitting process with the highest hydrogen production efficiency hitherto reported, with a H 2 production rate of 655 μmol g −1 h −1 , which could rival excellent photocatalysis system. This study highlights the potential of piezoelectric catalysis for overall water splitting.