Ti2NTx MXene/rGO nanocomposites: Optical tunning, functional bonding and electrochemical analysis for supercapacitor electrode application

Abstract

Ti2NTx MXene/rGO nanocomposites were prepared via a two-step chemical etching and reduction method. TEM confirmed the stacked multilayer structure with an average interplanar spacing of 0.2 nm and the formation of Ti2NTx/rGO QDs of size from 0.14 to 0.33 nm. The absorption of Ti2NTx MXene/rGO composites decreased from 5.59 to 4.53 eV with increasing rGO concentration due to quantum confinement and microstructural rearrangement of Ti2NTx MXene within the rGO network. Cyclic voltammetry showed a specific capacitance (Cp) of 47.6–247F/g at 5 mV/s in −0.2–0.8 V. Galvanostatic charge–discharge resulted in Cp of 329.14–1203.86F/g at 1 A/g in 1 M H2SO4. The highest capacitive retention of 84.3 % was observed after 5000 cycles for Ti2NTx MXene. Electrochemical impedance spectra revealed that the charge transfer rate was maximum in (Ti2NTx)0.50/rGO0.50 due to the lowest RCT of 7.23 Ω. From the corrosion test, the Icorr ranged from 3.73 to 5.79 µA, and the Vcorr ranged from −0.008 to 0.26 V in the Ti2NTx MXene/rGO composites. Ti2NTx MXene/rGO composite showed remarkable electrochemical properties in acid electrolytes, such as high Cp and corrosion resistance, making them intriguing materials for supercapacitor electrode application.