Oxygen evolution reaction on MoS2/C rods - robust and highly active electrocatalyst.

Recently, water oxidation or oxygen evolution reaction (OER) in electrocatalysis has attracted huge attention due to its prime role in water splitting, rechargeable metal-air batteries and fuel cells. Here, we demonstrate a facile and scalable fabrication method of a rod-like structure composed of molybdenum disulphide and carbon (MoS2/C) from parent 2D MoS2. These novel composite, induced via chemical vapor deposition (CVD) process, exhibits superior oxygen evolution performance(overpotential = 132 mV at 10 mA/cm2 and Tafel slope = 55.6 mv/dec)in an alkaline medium. Additionally, stability tests of the obtained structures at 10 mA/cm2 during 10 h followed by 20 mA/cm2 during 5 h and 50 mA/cm2 during 2.5 h have been performed and clearly prove that MoS2/C can be successfully used as robust noble-metal-free electrocatalysts.The promoted activity of the rods is ascribed to the abundance of active surface (ECSA) of the catalyst induced due to curvature effect during reshaping of the composite from 2D precursor (MoS2) in CVD process. Additionally, turnover frequency (TOF) (58 1/s at the current density of 10 mA/cm2), as a direct indicator of intrinsic activity, indicates the efficiency of this catalyst in oxygen evolution reaction (OER). Based on ex-situ analyses (XPS, XRD, Raman) of the electrocatalyst the possible reaction mechanism is explored and discussed in great details showing that MoS2, carbon and iron oxide are main active species of the reaction.&#xD.