A monolith electrode featuring FeS2 embedded in porous carbon nanofibers for efficient hydrogen evolution

Abstract

Constructing electrode materials embracing with high effectivity and durable stability is of vital importance for hydrogen evolution reaction (HER) in electrochemical water splitting. Herein, a monolith electrode is designed with FeS2 nanoparticles embedded in porous carbon nanofibers (FeS2@CNFs) via an in-situ electrospinning strategy, which is directly used as an efficient electrode for HER without any extra-substrates. Such monolithic electrode eliminates interface problems between active catalysts and carriers and expends more intrinsic catalysis regions, which effectively shortens the pathway of electron/ mass transport. The FeS2@CNFs electrode displays good HER activity only with an overpotential of 168 mV at 10 mA cm−2. It is worth noting that this monolith electrode shows the excellent HER stability for nearly a week in 1 M KOH without any destruction of fibrous structure. Such considerable activities can be ascribed to the interwoven nanofiber-meshes that engineer the self-supportive architecture with stable strength and the carbon-encapsulation structure that prevents FeS2 from collapsing. The woven meshes and porous structure allow the sufficient penetration of electrolyte and fast gas diffusion. This work provides a valuable reference for rationally designing a monolith electrode effectively for gas-involved electrochemical application.