An electrochemical anodization strategy towards high-activity porous MoS₂ electrodes for the hydrogen evolution reaction

Molybdenum disulfide (MoS₂) is a promising non-precious metal electrocatalyst for the hydrogen evolution reaction (HER). Herein, we have described an anodization route for the fabrication of porous MoS₂ electrodes. The active porous MoS₂ layer was directly formed on the surface of a Mo metal sheet when it was subjected to anodization in a sulfide-containing electrolyte. The Mo sheet served as both a supporter for MoS₂ electrocatalysts and a conductive substrate for electron transport. After optimizing the anodization parameters, the anodized MoS₂ electrode showed a high electrocatalytic activity with an onset potential of -0.18 V (vs. RHE) for the HER, a Tafel slope of ∼101 mV per decade and an overpotential of 0.23 V at a current density of 10 mA cm^-2 for the HER. These results indicate that our facile anodization strategy is an efficient route towards a high-activity MoS₂ electrode.