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

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.