Novel self-supported MoS2/FeS2 nanocomposite as an excellent electrocatalyst for hydrogen evolution

The development of earth-abundant electrocatalysts to replace high-cost precious metal Pt for water splitting to generate H2 is a hot topic in the researches on clean energy. Among them, MoS2 nanostructures have intrigued great interest for its low cost and potential high performance. However, due to the intrinsically low conductivity, its H2 evolution activity is not satisfactory as an applicable electrocatalyst. Herein we report a novel MoS2/FeS2 nanocomposite grown directly on carbon cloth by a facile method based on simple one-step chemical vapor deposition, which has significantly improved H2 evolution performance compared to its pure MoS2 nanosheets counterpart. Such self-supported MoS2/FeS2 nanocomposite electrode exhibits a relatively low overpotential of 134 mV at a current of 10 mA cm−2, a quite small Tafel slope of 76.8 mV⋅dec−1 and excellent electrocatalytic durability in 0.5 mol L−1 H2SO4. The remarkably high H2 evolution activity could be ascribed to the fully exposed and increased number of active sites, enhanced charge transfer rate between MoS2 nanosheets and FeS2 nanoparticles in the composite, and the 3D self-supported structure. This strategy to prepare MoS2/FeS2 nanocomposite with controllable morphology and highly active microstructure would provide a new way for the improvement of the electrocatalytic H2 evolution activity and durability of MoS2.