Revolutionizing energy: Vanadium pentoxide (V2O5) and molybdenum disulfide (MoS2) composite incorporated with GQDs as a dual-purpose material for supercapacitors and hydrogen evolution

Abstract

In the pursuit of developing electrode materials with versatile uses, including energy storage as well as facilitating the hydrogen evolution reaction (HER), extensive research efforts have been dedicated to this domain. A novel composite of V₂O₅@MoS₂ has been synthesized within this study and employed in asymmetric supercapacitors. The V₂O₅@MoS₂ electrode demonstrated a remarkable $\mathrm{Cs}$ of 1735C/g at a current density of 2.0 A/g through a comprehensive three-cell investigation. Remarkably, substantial specific surface area of 79.32 m²/g, was detected, ascertained through BET measurement, significantly augmenting its electrochemical performance. Showcasing specific charge capacity (Qs) of 312C/g, furthermore, the V₂O₅@MoS₂ composite was utilized in constructing the supercapattery device. Impressively, the device V₂O₅@MoS₂//AC delivered 57 Wh/kg energy at 1050 W/kg power density. Remarkably, attesting to its exceptional cyclic stability, the V₂O₅@MoS₂ device retained 95 % of its initial capacity, after undergoing 12,000 charge-discharge cycles. Moreover, the V₂O₅@MoS₂ composite demonstrated the lowest overpotential compared to 102 mV composites evaluated in a hydrogen evolution reaction (HER). This underscores the outstanding catalytic activity of the V₂O₅@MoS₂ electrode for HER applications, further validating its potential for utilization in energy storage devices.