Highly Efficient Flexocatalysis of Two-Dimensional Semiconductors.

Catalysis is vitally important for chemical engineering, energy and environment. It is critical to discover new mechanisms for efficient catalysis. For piezoelectric/pyroelectric/ferroelectric materials that have a non-centrosymmetric structure, interfacial polarization induced redox reactions at surfaces leads to advanced mechanocatalysis. Here, we demonstrate the first flexocatalysis for two-dimensional centrosymmetric semiconductors, such as MnO 2 nanosheets , largely expanding the polarization-based-mechanocatalysis to two-dimensional centrosymmetric materials. Under ultrasonic excitation, the reactive species are created due to the strain-gradient-induced flexoelectric polarization in MnO 2 nanosheets composed nanoflowers. The organic pollutants (MB et al.) can be effectively degraded within 5 minutes, the performance of the flexocatalysis is comparable to that of state-of-the-art piezocatalysis, with excellent stability and reproducibility. Moreover, the factors related to flexocatalysis such as material morphology, adsorption, mechanical vibration intensity, and temperature are explored, which give deep insights into the mechanocatalysis. This study opens the field of flexoelectric effect based mechanochemistry in two-dimensional centrosymmetric semiconductors. This article is protected by copyright. All rights reserved.