Robust Flexo‐Catalysis in Centrosymmetric Nanoparticles

Abstract

Flexoelectricity has trigged emergent phenomena and functionalities, such as flexo‐resistance, flexo‐photovoltaic, photo‐flexoelectric, flexo‐electronics and so on. Analogous to piezocatalysis, the flexoelectric effect can provide a novel mechanism to enhance the sonochemical redox reactions. Here, by extending flexoelectricity to electrochemical functionality, an unprecedented phenomenon is demonstrated of flexo‐catalysis effect in centrosymmetric nanoparticles to degrade organic dyes. Simulations have been performed to elucidate the bubble cavitation induced strain gradients and polarization variation, and in turn the flexoelectricity induced reactive species have been verified by trapping experiment. The flexo‐catalytic results show that more than 92.2% of Rhodamine B can be degraded at a rate of ≈k = 0.6 h−1. This finding not only suggests a new strategy to generate the flexoelectric effect, but also opens up the possibility to extend existing catalytic techniques.

Bi5Ti3FeO15 Nanofibers for Highly Efficient Piezocatalytic Degradation of Mixed Dyes and Antibiotics

“…Compared with the fresh nanofibers, there is only a very weak absorption peak at around 1250 cm –1 for the used nanofibers, indicating that the absorption effect is very weak. Recently, flexocatalysis has received much attention. , The flexocatalysis effect could happen in the piezocatalysis process, especially for two-dimensional single-crystal piezocatalyst . However, the Bi 5 Ti 3 FeO 15 nanofibers are composed of nanoparticles and when nanofibers are bent under ultrasonic vibration, these nanoparticles in nanofibers are deformed because of compression or tension.…”

Mechanoluminescent Light Sources Based on Nanostructured Systems for Biomedical Applications: A Review

“…On the other hand, the flexoelectric effect occurs when a strain gradient breaks the inversion symmetry, generating electric polarization in a preferred direction of dielectric materials. 37 Unlike the piezoelectric effect, the flexoelectric effect is not restricted to noncentrosymmetric crystal structures. Although flexoelectricity is typically weak in bulk materials due to low flexoelectric coefficients, it may become significant in nanosized ML materials due to the substantial strain gradients.…”

Research progress in enhancement strategies and mechanisms of piezo-electro-chemical coupling

“…(1) 压-电-化学耦合的物理机制尚有待完善：压-电-化学耦合是将力信号 (机械信号)转化为电信号并进一步参与化学反应。然而其中间的力-电转换过 程除了源自催化剂材料的压电效应，在理论上也有可能源自催化剂的挠曲电效 应或摩擦生电效应 [75,76] 。对于压电化学耦合实验现象的解释目前包括压电催化、 挠曲电催化和摩擦催化，未来需要对其具体的起源进行深入的研究和系统的甄 别。此外，目前尚未对压电化学耦合的中间过程，如载流子的产生与迁移过程 需要进行详细的理论与实验研究。在光-电-化学耦合过程，李灿等人采用表面光 电压谱直接观测到载流子的产生和迁移 [77] ，未来如何采用类似的方法对压-电-化…”