Department of Materials Science and Engineering, University of Wisconsin-Madison, USA.
Sci Rep. 2013;3:2160. doi: 10.1038/srep02160.
Recently, the strain state of a piezoelectric electrode has been found to impact the electrochemical activity taking place between the piezoelectric material and its solution environment. This effect, dubbed piezocatalysis, is prominent in piezoelectric materials because the strain state and electronic state of these materials are strongly coupled. Herein we develop a general theoretical analysis of the piezocatalysis process utilizing well-established piezoelectric, semiconductor, molecular orbital and electrochemistry frameworks. The analysis shows good agreement with experimental results, reproducing the time-dependent voltage drop and H₂ production behaviors of an oscillating piezoelectric Pb(Mg₁/₃Nb₂/₃)O₃-32PbTiO₃ (PMN-PT) cantilever in deionized water environment. This study provides general guidance for future experiments utilizing different piezoelectric materials, such as ZnO, BaTiO₃, PbTiO₃, and PMN-PT. Our analysis indicates a high piezoelectric coupling coefficient and a low electrical conductivity are desired for enabling high electrochemical activity; whereas electrical permittivity must be optimized to balance piezoelectric and capacitive effects.
最近，人们发现压电电极的应变状态会影响压电材料与其溶液环境之间发生的电化学活性。这种效应被称为压电化学，在压电材料中尤为明显，因为这些材料的应变状态和电子状态是强烈耦合的。在此，我们利用已建立的压电、半导体、分子轨道和电化学框架，对压电化学过程进行了一般理论分析。该分析与实验结果吻合较好，重现了在去离子水环境中振荡的压电 Pb(Mg₁/₃Nb₂/₃)O₃-32PbTiO₃ (PMN-PT) 悬臂的随时间变化的电压降和 H₂ 生成行为。本研究为未来利用不同压电材料（如 ZnO、BaTiO₃、PbTiO₃ 和 PMN-PT）的实验提供了一般性指导。我们的分析表明，为了实现高电化学活性，需要高的压电耦合系数和低的电导率；而介电常数必须优化以平衡压电和电容效应。
