Development of a novel method to grow mono-/few-layered MoS2 films and MoS2–graphene hybrid films for supercapacitor applications

Abstract

The controlled synthesis of highly crystalline MoS₂ atomic layers remains a challenge for practical applications of this emerging material. We demonstrate a facile method to synthesize crystalline mono-layered/few-layered MoS₂ thin films at the liquid–liquid interface which can be suitably transferred to the substrates. The films are characterized by XRD for their crystal structure and by SEM and TEM for the morphology. MoS₂ nanosheet–graphene nanosheet (MoS₂–GNS) hybrid films have been developed by the application of layer-by-layer (LbL) techniques. Cyclic voltammetry and other electrochemical characterization techniques reveal that the hybrid film electrode shows a specific capacitance of 282 F g⁻¹ at a scan rate of 20 mV s⁻¹. The as-obtained hybrid electrode is robust and exhibits much improved cycle life (>1000), retaining over 93% of its initial capacitance as revealed by galvanostatic charge/discharge studies. The confirmation of better performance as a supercapacitor of the composite was studied by electrochemical impedance spectroscopy. These results indicate that the MoS₂–GNS hybrid is a promising candidate for the electrode material in supercapacitor applications.