Facile decoration of two-dimensional Ti₃C₂T_x nanoplates with CuS nanoparticles via a facile in situ synthesis strategy at room temperature for superhigh specific capacitance of supercapacitors

Although supercapacitors have attracted more and more attention owing to their fast charging speed and high power density, their wide applications have still been limited by their low energy density. In this study, a new CuS-nanoparticle-decorated Ti₃C₂T_x electrode material is fabricated via a facile in situ synthesis strategy at room temperature. CuS nanoparticles, generated from the in situ reaction of Cu (NO₃)₂·3H₂O with Na₂S·9H₂O, are anchored between the Ti₃C₂T_x interlayers through electrostatic interaction. This type of structural construction is found capable of not only reducing the surface oxidation of Ti₃C₂T_x, but also preventing the accumulation of CuS nanoparticles by the template effect of Ti₃C₂T_x nanoplates. As a result, the CuS/Ti₃C₂T_x nanohybrid delivers a maximum specific capacitance of 911 F g⁻¹ at 1 A g⁻¹ and a good cycling stability. A symmetric supercapacitor fabricated using the CuS/Ti₃C₂T_x nanohybrid as the electrode material exhibits an energy density of 43.56 W h kg⁻¹ with a power density of 475 W kg⁻¹. Consequently, this work provides a new perspective of microstructural design for the preparation of electrode materials with superhigh specific capacitance through an easy and low-cost in situ-reaction method at room temperature.