Electrodeposited carbon-supported nickel sulfide thin films with enhanced stability in acid medium as hydrogen evolution reaction electrocatalyst

A single-step electrochemical deposition of NiS thin films incorporating various carbon nanomaterials as support is described. Advantages of this method are as follows: It is simpler and can be easily scaled up, the precursors employed are cheaper, and the deposition method is energy effective requiring no further heat treatments. Benefits of carbon nanomaterials as catalyst support are manifold including high conductivity and stability. The carbon-supported thin films exhibit high hydrogen evolution activity, low Tafel slopes, and improved double layer capacitance. A remarkable enhancement in the stability of the thin films in the acid medium has been observed. Specifically, NiS/carbon nanofibers have shown the highest activity, lowest Tafel slope, and retained more than 90% of its initial activity after the stability tests.