MoS2 nanorods anchored reduced graphene oxide nanohybrids for electrochemical energy conversion applications

Abstract

Herein, the hydrothermal route has been explored to design a novel network of molybdenum sulfide (MoS 2 ) nanorods/reduced graphene oxide (rGO) by varying wt% of MoS 2 (10–30 wt%) for the highly stable and efficient electrochemical energy conversion applications involving dye sensitized solar cells (DSSCs); and direct methanol fuel cells (DMFCs). The MoS 2 /rGO nanohybrids network has been systematically characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). XRD, HRTEM, Raman and XPS investigations confirmed the uniform and homogenous anchoring of MoS 2 nanorods on the rGO sheets in the MoS 2 /rGO nanohybrids. It has been revealed that the wt% of MoS 2 in MoS 2 /rGO nanohybrids strongly affects the anchoring of MoS 2 nanorods on rGO sheets which in turn affects their electrocatalytic behavior. The optimized MoS 2 /rGO nanohybrids with 20 wt% of MoS 2 nanorods exhibited long term stability and highly efficient electrocatalytic behavior. DSSCs assembled with MoS 2 /rGO nanohybrids as CE exhibited comparable power conversion efficiency (PCE) relative to standard DSSC. The optimized anchoring of MoS 2 on rGO sheets resulted in high current density as compared to rGO based electrocatalyst in MORs. Moreover, reproducibility of CV curves revealed high stability of MoS 2 /rGO nanohybrids under harsh electrolyte medium. • Synthesis of novel network of molybdenum sulfide nanorods (MoS 2 )/ reduced graphene oxide (rGO) using hydrothermal method. • Optimized MoS 2 /rGO nanohybrids (20 wt% of MoS 2 ) exhibits long term stability and high electrocatalytic behavior. • MoS 2 /rGO nanohybrids act as effective replacement of Pt electrocatalyst in DSSCs and methanol oxidation reactions in DMFCs.