Vanadium carbide and nitrogen-doped graphene nanosheets based layered architecture for electrochemical evaluation of clioquinol detection and energy storage application

• Oxygen-containing functional groups were tailored over the MXenes vanadium carbide layers. • layered architecture of oxidized vanadium carbide (V 8 C 7 Tx)/Nitrogen-doped graphene-based nanocomposite has been constructed. • The nanocomposite has been utilized for clioquinol (antibiotic drug) for the first time. • The nanocomposite exhibits high energy storage performance and cycling stability. Herein, we report the oxidized-vanadium carbide (V 8 C 7 Tx) hybridized with nitrogen-doped graphene nanosheets (VC/NG NSs) nanocomposite using hydrothermal followed by sonochemical approach. The oxidized V 8 C 7 Tx is shown to be enriched with O-terminated functional groups, which also improves the electrochemical performance of the nanocomposite. Then for the first time, VC/NG NSs nanocomposite is reported as an efficient electrocatalyst for the detection of CQL. The cyclic voltammetry (CV) experiments were performed at the working potential from 0 to 0.7 V (vs. Ag/AgCl). Surprisingly, the nanocomposite's multilayer structure offers a large number of active sites with a high electron transfer rate for CQL detection. The fabricated drug sensor exhibits a lower oxidation potential (0.46 V) and a greater peak current response (12.05 µA) than previously reported sensors. Under optimum circumstances, the fabricated sensors analytically well performed by means of low detection limit (9 nM), wide linear range (0.5–585 µM), and appreciable recovery results (∼98%, ( n = 3)) in human urine samples. Furthermore, the nanocomposite shows a high gravimetric capacitance of 235 F g −1 at 1 A g −1 in 1 M KOH, which is the highest value among alkali-based electrolytes for VC based electrodes. Moreover, the nanocomposite demonstrated robust cycling performance even after 8000 cycles with ∼95% capacitance retention. The presence of O-terminated functional groups, various oxidation states of vanadium (+2, +3, and +4), good conducting and catalytic characteristics of N-graphene are worked together to improve electrochemical performance in sensor and energy storage. Thus, the current study offers a promising MXene based nanocomposite material for high-performance electrochemical applications.