Oxygen Reduction Reaction Investigations of Ni/MoS2 and Ni/MoS2-rGO Hybrid Catalysts for Fuel Cells Applications

Abstract Due to its layered structure and appropriate electronic configuration, two-dimensional MoS2 has been considered a reliable and inexpensive electrocatalyst and electrode material for the oxygen reduction reaction (ORR). Additionally, the MoS2 and reduced graphene oxide (rGO) structure can act as a good host for other nanocatalysts. However, the catalytic activity of pristine MoS2 is not as effective as the industrial targeted values. In this work, Nickel-MoS2 (Ni/MoS2) and Ni/MoS2-rGO composites are synthesized and evaluated as catalysts for ORR at the cathode. Electrochemical studies using a rotating disk electrode system confirmed that the as-synthesized catalyst exhibits good electrocatalytic activity to ORR in alkaline media (0.1 M KOH) and followed the desirable 4e− transfer process. Ni/MoS2-rGO composite displays a current density of ‒11.1 mA/cm2 and onset potential of 0.87 V at 2400 rpm, whereas bare MoS2 shows the values of limiting current density and onset potential of ‒5.8 mA/cm2 and 0.79 V respectively. Numerous highly active Mo sites, high conductivity, and high specific surface area in MoS2-rGO make it a novel catalyst material for ORR. Ni further enhances conductivity and is involved in electrochemical reactions. Therefore, Ni/MoS2-rGO composite can be a good candidate for electrode catalyst material for alkaline fuel cells.