Mesoporous Iron Sulfide for Highly Efficient Electrocatalytic Hydrogen Evolution

We report a facile synthetic protocol to prepare mesoporous FeS₂ without the aid of hard template as an electrocatalyst for the hydrogen evolution reaction (HER). The mesoporous FeS₂ materials with high surface area were successfully prepared by a sol-gel method following a sulfurization treatment in an H₂S atmosphere. A remarkable HER catalytic performance was achieved with a low overpotential of 96 mV at a current density of 10 mA·cm^-2 and a Tafel slope of 78 mV per decade under alkaline conditions (pH 13). The theoretical calculations indicate that the excellent catalytic activity of mesoporous FeS₂ is attributed to the exposed (210) facets. The mesoporous FeS₂ material might be a promising alternative to the Pt-based electrocatalysts for water splitting.