Anisotropic Plasmon Resonance in Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXene Enables Site-Selective Plasmonic Catalysis
Zhiyi Wu, Jiahui Shen, Zimu Li, Shuang Liu, Yuxuan Zhou, Kai Feng, Binbin Zhang, Shiqi Zhao, Di Xue, Jiari He, Kewei Yu, Jinpan Zhang, Graham Dawson, Qingfeng Zhang, Lizhen Huang, Chaoran Li, Xingda An, Lifeng Chi, Xiaohong Zhang, Le He
Abstract
The ever-growing interest in MXenes has been driven by their distinct electrical, thermal, mechanical, and optical properties. In this context, further revealing their physicochemical attributes remains the key frontier of MXene materials. Herein, we report the anisotropic localized surface plasmon resonance (LSPR) features in Ti 3 C 2 T x MXene as well as site-selective photocatalysis enabled by the photophysical anisotropy. Both experimental and theoretical studies provide direct evidence of the occurrence of transverse and longitudinal dipolar plasmon resonance modes, respectively, driven by in-plane and out-of-plane vibrations of the two-dimensional (2D) MXene nanoflakes. Wavelength-controlled excitation of the two LSPR modes is demonstrated to activate either the on-edge or the in-plane active sites for plasmonic charge carrier-induced site-selective catalysis. Our findings uncover the presence as well as the mechanism of the anisotropic plasmon resonance in nonmetallic 2D nanomaterials and provide intriguing design principles for next-generation plasmonic nanocatalysts.