Effect of electrolyte optimization on nitrogen-doped MXene (Ti3C2Tx) coupled with Cu–BTC MOF for a supercapattery and the hydrogen evolution reaction

Abstract

Recently, many studies have been done on MXene (2D titanium carbide) for energy storage applications. It possesses outstanding features like hydrophobicity, conductivity, and particularly strong surface redox reactivity, which are essential for energy storage applications. Despite these exceptional properties, MXene's electrochemical performance is significantly impacted by certain deficiencies, such as the inability to assemble MXene sheets. To prevent MXene sheets from restacking, the spaces between them must be filled with an appropriate material. Metal–organic frameworks (MOFs) for electrochemical applications have also been extensively studied. Due to their high crystallinity, porous structure, and substantial surface area, MOFs find diverse applications, but their efficacy as electrode materials is hindered by a lower specific capacity and charging/discharging rate. Addressing these limitations, combining MOFs with suitable materials is preferred for enhanced performance. This study suggests an innovative approach: a composite between Cu–BTC MOF and N–MXene. By shortening both the ion/electron diffusion pathways and improving the electroactive sites, the prevention of MXene sheet restacking was achieved, leading to exceptional specific and rate capacity in the composite with MOFs. The Cu–BTC/N–MXene-decorated electrode exhibited energy and power density reaching approximately 65.23 W h kg⁻¹ and 923 W kg⁻¹ in a two-electrode (real device) configuration. Cu–BTC/N–MXene//N–MXene retained 99% of its capacity and a coulombic efficiency of 92% after 8000 alternate GCD cycles. The findings of this investigation highlight the significant potential of employing the innovative electrode material Cu–BTC/N–MXene for supercapattery applications.