FeS₂-doped MoS₂ nanoflower with the dominant 1T-MoS₂ phase as an excellent electrocatalyst for high-performance hydrogen evolution

Well-established methods to improve the hydrogen evolution reaction (HER) performances include, but are not limited to, tailoring the morphology and electronic structure of transition metal dichalcogenides (TMDs), and doping of earth abundant chemicals such as iron pyrite FeS₂ into existing TMDs. In this work, MoS₂ nanoflowers with the majority being octahedral MoS₂ (1T-MoS₂) and doped with FeS₂ were prepared and applied to HER. The as-prepared catalysts were characterized by X-ray absorption fine structure at the K-edge of Mo, S, and Fe to probe the local electronic structures. The resulting nanomaterial was identified to be FeS₂ doped MoS₂ nanoflower (denoted as Fe-MoS₂NF) with 66% 1T-MoS₂ which was the metallic phase and could drastically boost the HER properties. The Fe-MoS₂NF exhibited high HER performance with a Tafel slope of 82 mV dec⁻¹ and it needs 136 mV to achieve a current density of 10 mA cm⁻². The synthesis of Fe-MoS₂NF with refined morphology and active electronic structure is expected to open a new era for improving the catalytic activity and stability of MoS₂.