TY - JOUR AU - Song, Fei AU - Hu, Jian AU - Li, Guohao AU - Wang, Jie AU - Chen, Shuijiao AU - Xie, Xiuqiang AU - Wu, Zhenjun AU - Zhang, Nan PY - 2021/12/17 Y2 - 2024/03/29 TI - Room-Temperature Assembled MXene-Based Aerogels for High Mass-Loading Sodium-Ion Storage JF - Nano-Micro Letters JA - Nano-Micro Lett VL - 14 IS - SE - Articles DO - 10.1007/s40820-021-00781-6 UR - https://nmlett.org/index.php/nml/article/view/1024 SP - 37 AB - <p>Low-temperature assembly of MXene nanosheets into three-dimensional (3D) robust aerogels addresses the crucial stability concern of the nano-building blocks during the fabrication process, which is of key importance for transforming the fascinating properties at the nanoscale into the macroscopic scale for practical applications. Herein, suitable cross-linking agents (amino-propyltriethoxysilane, Mn<sup>2+</sup>, Fe<sup>2+</sup>, Zn<sup>2+</sup>, and Co<sup>2+</sup>) as interfacial mediators to engineer the interlayer interactions are reported to realize the graphene oxide (GO)-assisted assembly of Ti<sub>3</sub>C<sub>2</sub>T<sub><em>x</em></sub> MXene aerogel at room temperature. This elaborate aerogel construction not only suppresses the oxidation degradation of Ti<sub>3</sub>C<sub>2</sub>T<sub><em>x</em></sub> but also generates porous aerogels with a high Ti<sub>3</sub>C<sub>2</sub>T<sub><em>x</em></sub> content (87 wt%) and robustness, thereby guaranteeing the functional accessibility of Ti<sub>3</sub>C<sub>2</sub>T<sub><em>x</em></sub> nanosheets and operational reliability as integrated functional materials. In combination with a further sulfur modification, the Ti<sub>3</sub>C<sub>2</sub>T<sub><em>x</em></sub> aerogel electrode shows promising electrochemical performances as the freestanding anode for sodium-ion storage. Even at an ultrahigh loading mass of 12.3&nbsp;mg&nbsp;cm<sup>−2</sup>, a pronounced areal capacity of 1.26 mAh cm<sup>−2</sup> at a current density of 0.1 A g<sup>−1</sup> has been achieved, which is of practical significance. This work conceptually suggests a new way to exert the utmost surface functionalities of MXenes in 3D monolithic form and can be an inspiring scaffold to promote the application of MXenes in different areas.</p><p>Highlights:</p><p>1 Room temperature graphene oxide-assisted assembly of 3D Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> MXene aerogels have been realized by introducing interfacial mediators (amino-propyltriethoxysilane, Mn<sup>2+</sup>, Fe<sup>2+</sup>, Zn<sup>2+</sup>, and Co<sup>2+</sup>).<br>2 The methodology not only suppresses the oxidation degradation of Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub>, but also generates porous aerogels with a high Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> content (87 wt%) and robustness.<br>3 As freestanding electrode of the as-prepared Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub>-based aerogel with a practical-level mass loading of 12.3 mg cm<sup>-2</sup> still delivers an areal capacity of 1.26 mAh cm<sup>-2</sup> at a current density of 0.1 A g<sup>-1</sup>.</p> ER -