Synergetic effect between MoS2 and N, S- doped reduced graphene oxide supported palladium nanoparticles for hydrogen evolution reaction

An active, stable, and relatively low-cost electrocatalyst is crucial in the sustainable production of hydrogen through water electrolysis. In this work, the electrocatalytic activity of Pd supported on MoS2 and nitrogen, sulfur-doped reduced graphene oxide (Pd/MoS2/N,S-rGO) was investigated by two-step hydrothermal method followed by chemical reduction of Pd using sodium borohydride (NaBH4). The Structural and morphological structure of the sample was studied by using X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscope (HRTEM) techniques. The electrochemical hydrogen evolution (HER) performance of the electrocatalyst was studied by using Linear Sweep Voltammetry (LSV), Electrochemical Impedance Spectroscopy (EIS), and Chronoamperometry (CA). The result shows a structural transformation in the MoS2 phase after the incorporation of Pd nanoparticles. The synthesized (Pd/MoS2/N,S-rGO) electrocatalyst shows a significantly lower overpotential of -42 mV vs. RHE at 10 mA/cm(2) and Tafel slope value of 38 mV.dec(-1). This study demonstrated with low palladium loading, the high activity of the electrocatalyst could have resulted from the cumulative effect of 1T MoS2, sulfur vacancy formation, and higher surface area of N,S-rGO.