Exploring the electrochemical characteristics of the nucleobase-template assisted NiCo2O4 electrode for supercapacitors

Abstract

Metal–nucleobase nanostructures are considered essential electrode materials in demonstrating the electrochemical performance of supercapacitors for energy storage devices. In this study, different combinations of nucleobases have been used as metal coordination ligands to prepare the NiCo₂O₄ (NCO) nanostructures. Of specific interest, the nucleobases such as adenine (A), guanine (G), and cytosine (C) were used in different combinations such as A–G, A–C, and G–C for modulating the structure and morphology of NCO. Owing to the synergistic effect of higher electronic conductivity and sheet-like morphology, the NCO/A–G obtained from the Ni–Co/A–G complex shows enhanced supercapacitance characteristics relative to that of the NCO nanostructures obtained using other combinations (A–C and G–C). In particular, the NCO/A–G as an electrode material shows a maximum specific capacity of ∼130 mA h g⁻¹ at a current density of 0.3 A g⁻¹. Significantly, the fabricated asymmetric supercapacitor (ASC) consisting of six-series cells extends the operating voltage of 6.5 V with good energy and power density of 8.5 μW h cm⁻² and 400 μW cm⁻², respectively. It is also demonstrated that the NCO/A–G-based supercapacitor effectively lights up a blue light-emitting diode for a certain time, suggesting the feasibility of morphologically tuned nucleobase–metal complexes for practical energy storage devices.