Publication
Engineering Sub‐Nanometer Hafnia‐Based Ferroelectrics to Break the Scaling Relation for High‐Efficiency Piezocatalytic Water Splitting
Publisher:
Wiley
Date:
15-09-2023
DOI:
10.1002/ADMA.202303018
Abstract: 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 0.5 Zr 0.5 O 2 (HZO) nanowires with a polymer‐like flexibility have been synthesized. Oxygen K‐edge X‐ray absorption spectroscopy (XAS) and negative spherical aberration‐corrected transmission electron microscope (NCS‐TEM) reveal an orthorhombic ( Pca2 1 ) ferroelectric phase of the HZO sub‐nanometer wires (SNWs). The ferroelectric polarization of flexible HZO SNWs can be easily switched by slight external vibration, resulting in a 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 a H 2 production rate of 25687 μm ol g −1 h −1 under 40 kHz ultrasonic vibration, which is 235 and 41 times higher than those of non‐ferroelectric hafnium oxides and rigid BaTiO 3 nanoparticles, respectively. More strikingly, the hydrogen production rates can reach 5.2 μm ol g −1 h −1 by addition of stirring exclusively. This article is protected by copyright. All rights reserved