Low-Dimensional Hyperthin FeS₂ Nanostructures for Efficient and Stable Hydrogen Evolution Electrocatalysis

We report a scalable, solution-processing method for synthesizing low-dimensional hyperthin FeS₂ nanostructures, and we show that 2D FeS₂ disc nanostructures are an efficient and stable hydrogen evolution electrocatalyst. By changing the Fe:S ratio in the precursor solution, we were able to preferentially synthesize either 1D wire or 2D disc nanostructures. The 2D FeS₂ disc structure has the highest electrocatalytic activity for the hydrogen evolution reaction, comparable to platinum in neutral pH conditions. Moreover, the ability of the FeS₂ nanostructures to generate hydrogen was confirmed by scanning electrochemical microscopy, and the 2D disc nanostructures were able to generate hydrogen for over 125 h.