Ti3C2Tx/TiO2@GO* Heterostructure: A Strategy to Design High-Specific Capacitive Electrodes for a Solid-State Supercapacitor

Herein, we report a facile approach to synthesize a 2D nanocomposite of MXene (Ti3C2Tx) and mechanically activated graphene oxide (denoted as GO*). A single-step solid-state reduction method was used to form GO*. Morphological and structural analyses show the formation of MXene wrapped with GO* nanosheets. The capacitive properties of all the synthesized nanocomposites were evaluated in the three-electrode system in an acidic environment, followed by device testing. The optimized Ti3C2Tx/TiO2@GO-9* electrode delivers a specific capacitance of 930.8 F g–1 at 1 A g–1, thus exhibiting superior electrochemical charge intake. Furthermore, it shows ∼98.2% retention in activity after 50k durability cycles under the harsh acidic medium. In addition to this, it is observed that the as-assembled symmetric supercapacitor demonstrates a specific capacitance of 82.7 F g–1 with a highest specific energy of 11.4 Wh kg–1 and a specific power of 2498 W kg–1 at 5 A g–1. The strong interaction between the GO* nanosheets having a high surface area and the highly porous MXene facilitates easy diffusion of the ions, resulting in superior electrochemical performance. Thus, our study provides a feasible strategy for the structural regulation and performance improvement of MXene-based supercapacitors.