Wu Tong, Liu Kang, Liu Shuhai, Feng Xiaolong, Wang Xuefeng, Wang Longfei, Qin Yong, Wang Zhong Lin
Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 101400, China.
School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049, China.
Adv Mater. 2023 Jan;35(3):e2208121. doi: 10.1002/adma.202208121. Epub 2022 Dec 16.
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, the first flexocatalysis for 2D centrosymmetric semiconductors, such as MnO nanosheets, is demonstrated largely expanding the polarization-based-mechanocatalysis to 2D centrosymmetric materials. Under ultrasonic excitation, the reactive species are created due to the strain-gradient-induced flexoelectric polarization in MnO nanosheets composed nanoflowers. The organic pollutants (Methylene Blue et al.) can be effectively degraded within 5 min; 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 2D centrosymmetric semiconductors.
催化对于化学工程、能源和环境至关重要。发现高效催化的新机制至关重要。对于具有非中心对称结构的压电/热释电/铁电材料，表面界面极化诱导的氧化还原反应导致先进的机械催化。在此，首次展示了二维中心对称半导体（如MnO纳米片）的挠曲催化，极大地将基于极化的机械催化扩展到二维中心对称材料。在超声激发下，由于由纳米花组成的MnO纳米片中应变梯度诱导的挠曲电极化而产生反应性物种。有机污染物（亚甲基蓝等）可在5分钟内有效降解；挠曲催化性能与最先进的压电催化相当，具有出色的稳定性和可重复性。此外，还探索了与挠曲催化相关的因素，如材料形态、吸附、机械振动强度和温度，这为机械催化提供了深入见解。本研究开启了二维中心对称半导体中基于挠曲电效应的机械化学领域。
