Two-dimensional transition-metal carbides and nitrides, often known as MXenes, have fantastic properties benefiting from their unique structures, enabling them to be used in many applications. In this work, we show that Ti₂C MXene possesses extraordinary electromechanical actuation performance using first-principles calculations. Upon charge injection, the maximum uniaxial and biaxial isometric actuation stresses are 31.1 (along the armchair direction) and 75.6 GPa, respectively, and the maximum isobaric actuation strain is 27.4%. More importantly, the electromechanical actuation of Ti₂C MXene is in-plane isotropic because of the 3-fold rotational symmetry, and the in-plane area can be stimulated to increase by 62.2%, which is greater than other well-known two-dimensional materials. The maximum realistic gravimetric work density of Ti₂C MXene is also extraordinary (1271.6 J/g). Finally, the mechanism for the extraordinary electromechanical actuation performance of Ti₂C MXene was elucidated by the analyses at atomic and electronic scales. Additionally, mechanical tests show that the structural integrity of Ti₂C MXene can be well maintained under a certain amount of electromechanical loads. Our findings indicate that Ti₂C MXene can be used for high-performance nanoelectromechanical actuators.

中文翻译：

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Ti ₂ C MXene的非常规机电驱动

二维过渡金属碳化物和氮化物（通常称为MXenes）得益于其独特的结构，具有出色的性能，使其可以用于许多应用中。在这项工作中，我们证明使用第一性原理计算，Ti ₂ C MXene具有非凡的机电驱动性能。注入电荷后，最大单轴和双轴等距激励应力分别为31.1（沿扶手椅方向）和75.6 GPa，最大等压激励应变为27.4％。更重要的是，Ti ₂的机电致动由于三重旋转对称性，C MXene是平面内各向同性的，并且可以刺激平面内面积增加62.2％，这比其他众所周知的二维材料要大。Ti ₂ C MXene的最大实际重量工作密度也非常高（1271.6 J / g）。最后，通过原子和电子尺度的分析阐明了Ti ₂ C MXene具有非凡的机电驱动性能的机理。另外，机械测试表明，在一定量的机电负载下，可以很好地保持Ti ₂ C MXene的结构完整性。我们的发现表明，Ti ₂ C MXene可用于高性能纳米机电致动器。