Supercapacitve performance of chemically exfoliated and CVD grown MoS2: A comparative study

Abstract

Two-dimensional (2D) metal dichalcogenides, like molybdenum disulfide (MoS2), have been demonstrated as extremely efficient supercapacitive electrode material due to their high electrical conductivity and surface area. Herein, two different methodologies are adopted to synthesize MoS2 samples: lithium (Li) intercalated chemical exfoliation and chemical vapour deposition (CVD) techniques. The structural and morphological characterizations of the as-prepared Li intercalated and CVD grown MoS2 were done by high resolution transmission electron microscopy (HRTEM) and Scanning electron microscopy (SEM). The Raman spectra show that the Li intercalated MoS2 samples are mostly comprised of 3–4 layers whereas a monolayer signature is observed in CVD grown samples. In this study, we report a comparative study of the supercapacitive properties of chemically exfoliated and CVD grown MoS2 using an electrochemical cell arrangement. Interestingly, the cyclic voltammetry (CV) result shows higher current density in CVD grown MoS2 as compared to that of Li intercalated MoS2 samples. The observed high specific capacitance can be ascribed to a larger surface area in CVD grown MoS2 owing to a higher charge transfer facilitating the diffusion of electrolyte ions. This result shows that the CVD grown MoS2 can be used for high performance supercapacitor applications.