Functionalized Ketjenblack Infusion into Expanded Interlayer Spacing of Ti₃C₂T_x MXene Nanosheets toward High Specific Capacitance Supercapacitors

Mass-producible, high-specific-capacitance, long-term-stability, miniature power sources are crucial to automobiles, elevators, and lately to power biosensors in cancer biomarker detection by integrating them into analytical systems and in miniaturized implantable cancer therapy devices. Ketjenblack (KB) is one of the best-used carbonaceous additives in electrode fabrication due to its mass productivity at low cost, large specific surface area, good charge–discharge performance, and remarkable electrical conductivity at low weight ratios. In this work, functionalized KB (f-KB) has been infused into the interlayers of Ti 3 C 2 T x MXene sheets to enrich electronic transport and structural stability. The 2D arrangement of MXene aids for the higher electrochemical active sites and larger interlayer spacing to noteworthy enhanced electrode surface’s space utilization. Thus, we report a new approach of orbital shaking to synthesize delaminated MXene (TMMX) using tetramethylammonium hydroxide for the first time, and the prepared f-KB@TMMX composite-modified graphite sheet (GS) was utilized as an electrode material in a supercapacitor (SC). The 2D structure of the combined composite of delaminated MXene infused with nanospherical f-KB particles was characterized via XRD, FESEM, TEM, and XPS for the structural and functional group confirmations. The as-prepared f-KB@TMMX/GS electrode presented the highest specific capacitance of 292 Fg 1– at a current density of 0.5 Ag 1– and superior long cyclic stability of 78% retention after 5000 charge–discharge cycles compared to exfoliated MXene (ExMX) and TMMX-modified GSs without f-KB infusion. In brief, the results specify that the promising structure of delaminated MXene and superior conductivity of f-KB further improved the wettability, structural stability, controlled self-restacking, and electronic conductivity herein.