FeS2-anchored transition metal single atoms for highly efficient overall water splitting: a DFT computational screening study

Abstract

Hydrogen production from water electrolysis using renewable electricity is widely regarded as a highly promising route to solve the energy crisis of human society. However, the rational design of low-cost electrocatalysts with excellent catalytic activity and long-term durability toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) remains a significant challenge. Herein, we reported a systematic density functional theory (DFT) study on the screening of FeS₂-supported transition metal single atoms (M@FeS₂) as electrocatalysts for the HER and OER. The results indicate that M@FeS₂ catalysts exhibit excellent thermal stability and good electrical conductivity for electrochemical reactions. Transition metal atoms are identified as the active sites for the HER and OER. Cr@FeS₂ and V@FeS₂ exhibit excellent catalytic activity towards the HER. In particular, Cr@FeS₂ has a ΔG_H* value of 0.049 eV and presents a lower activation energy barrier of 0.22 eV for the HER. The HER activity of Cr@FeS₂ is even higher than that of the current most efficient Pt catalysts. Mn@FeS₂ shows good OER activity and is expected to be a promising candidate for OER electrocatalysts. This work could pave a new way to design cost-effective electrocatalysts for the HER and OER, and also shed light on the application of FeS₂-based materials in water splitting.