Facile decoration of two-dimensional Ti 3 C 2 T x nanoplates with CuS nanoparticles via a facile in situ synthesis strategy at room temperature for superhigh specific capacitance of supercapacitors

Abstract 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 Ti 3 C 2 T 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 (NO 3 ) 2 ·3H 2 O with Na 2 S·9H 2 O, are anchored between the Ti 3 C 2 T x interlayers through electrostatic interaction. This type of structural construction is found capable of not only reducing the surface oxidation of Ti 3 C 2 T x , but also preventing the accumulation of CuS nanoparticles by the template effect of Ti 3 C 2 T x nanoplates. As a result, the CuS/Ti 3 C 2 T 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/Ti 3 C 2 T 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.