Su Ran, Zhang Jiahui, Wong Vienna, Zhang Dawei, Yang Yong, Luo Zheng-Dong, Wang Xiaojing, Wen Hui, Liu Yang, Seidel Jan, Yang Xiaolong, Pan Ying, Li Fa-Tang
Hebei Key Laboratory of Photoelectric Control on Surface and Interface, College of Science, Hebei University of Science and Technology, Shijiazhuang, 050018, P. R. China.
School of Materials Science and Engineering, University of New South Wales Australia, Sydney, New South Wales, 2052, Australia.
Adv Mater. 2023 Oct;35(42):e2303018. doi: 10.1002/adma.202303018. Epub 2023 Sep 15.
Reversible control of ferroelectric polarization is essential to overcome the heterocatalytic kinetic limitation. This can be achieved by creating a surface with switchable electron density; however, owing to the rigidity of traditional ferroelectric oxides, achieving polarization reversal in piezocatalytic processes remains challenging. Herein, sub-nanometer-sized Hf Zr O (HZO) nanowires with a polymer-like flexibility are synthesized. Oxygen K-edge X-ray absorption spectroscopy and negative spherical aberration-corrected transmission electron microscopy reveal an orthorhombic (Pca2 ) ferroelectric phase of the HZO sub-nanometer wires (SNWs). The ferroelectric polarization of the flexible HZO SNWs can be easily switched by slight external vibration, resulting in dynamic modulation of the binding energy of adsorbates and thus breaking the "scaling relationship" during piezocatalysis. Consequently, the as-synthesized ultrathin HZO nanowires display superb water-splitting activity, with H production rate of 25687 µmol g h under 40 kHz ultrasonic vibration, which is 235 and 41 times higher than those of non-ferroelectric hafnium oxides and rigid BaTiO nanoparticles, respectively. More strikingly, the hydrogen production rates can reach 5.2 µmol g h by addition of stirring exclusively.
铁电极化的可逆控制对于克服异相催化动力学限制至关重要。这可以通过创建具有可切换电子密度的表面来实现；然而，由于传统铁电氧化物的刚性，在压电催化过程中实现极化反转仍然具有挑战性。在此，合成了具有类聚合物柔韧性的亚纳米尺寸的Hf Zr O（HZO）纳米线。氧K边X射线吸收光谱和负球差校正透射电子显微镜揭示了HZO亚纳米线（SNW）的正交（Pca2 ）铁电相。柔性HZO SNW的铁电极化可以通过轻微的外部振动轻松切换，从而导致吸附质结合能的动态调制，进而打破压电催化过程中的“比例关系”。因此，合成的超薄HZO纳米线表现出出色的水分解活性，在40kHz超声振动下产氢速率为25687µmol g h，分别是非铁电铪氧化物和刚性BaTiO纳米颗粒的235倍和41倍。更引人注目的是，仅通过搅拌，产氢速率就可以达到5.2µmol g h。
