MXene enhanced reduced graphene oxide aerogel for high-performance supercapacitors

Three-dimensional (3D) reduced graphene oxide (rGO)/Ti 2 CT x MXene hybrid aerogels were effectively prepared by a two-step method involving hydrothermal reaction and freeze-drying. The intimately coupled rGO/Ti 2 CT x hybrid aerogel combined high electrical conductivity, large interlayer spacing, and excellent mechanical stability of Ti 2 CT x , which not only effectively prevents the self-restacking of Ti 2 CT x nanosheets, exposes more active sites exposed, and improves the volume change during the charge/discharge process but also increases the accessibility of ions and promotes the rapid transfer of ions/electrons. As a result, rGO/Ti 2 CT x 17.5–2.5 as the working electrode of electric double layer capacitors delivers a large specific capacity (107.05 F g −1 at 0.5 A g −1 in a 1M Na 2 SO 4 electrolyte), a high rate capability (maintains 30% of its initial capacitance at 10 A g −1 , which is much better than rGO and Ti 2 CT x ), and excellent long-term large-current cycle stability (the initial capacitance remains above 71.1% after 10 000 cycles at 1 A g −1 ). In addition to providing a high-performance electrode for supercapacitors, this study proposes an efficient and time-saving strategy for constructing 3D structures from 2D materials.