Electronic structure modulation of NiS2 by transition metal doping for accelerating the hydrogen evolution reaction

Abstract

As a narrow bandgap semiconductor, NiS₂ is promising to be an efficient electrocatalyst towards hydrogen evolution reactions (HER) by regulating the local electronic structure. The mechanism of transition metal doping to improve the electrocatalytic performance of NiS₂ is not comprehensively reported yet. To this end, we first conduct systematic research on the HER activity of transition metal-doped NiS₂ electrocatalysts by first principles calculations. The results indicate that dopants can activate more HER active sites and improve the electrical conductivity of NiS₂, where the Fe element is demonstrated to be the best candidate. Experimentally, the electrochemical measurement results reveal that Fe-doped NiS₂ electrocatalysts have enhanced HER electrocatalytic performance and great durability compared to pure NiS₂. This work provides a path for the rational design of HER electrocatalysts by transition metal doping.