Construction of FeS2@MoS2 heterostructures for enhanced hydrogen evolution

Abstract

The exploration of cheap and high-performance electrocatalysts is the key to developing clean hydrogen energy. Although MoS₂ is a good candidate to replace noble metal Pt-based electrocatalysts for the hydrogen evolution reaction (HER), the comprehensive performances are still unsatisfactory. In this work, FeS₂@MoS₂ heterostructures are proposed and constructed by a facile and low-cost method. Compared with single MoS₂, FeS₂ and their mixture (MoS₂ + FeS₂), the as-designed FeS₂@MoS₂ electrocatalyst possesses the best catalytic activity for the HER with a small Tafel slope of 58 mV dec⁻¹ as well as good stability. The experimental and calculation results confirm that the enhanced HER performance of FeS₂@MoS₂ should be attributed to the more exposed active sites, better charge transfer ability, and optimized free energy of hydrogen adsorption originating from the construction of FeS₂@MoS₂ heterostructures.