The effect of heteroatom doping on the active metal site of CoS2 for hydrogen evolution reaction

Abstract

The exploration of cost-effective hydrogen evolution reaction (HER) electrocatalysts through water splitting is important for developing clean energy technology and devices. The application of CoS₂ in HER has been drawing more and more attention due to its low cost and relatively satisfactory HER catalytic performance. And CoS₂ was found to exhibit excellent HER catalytic performance after appropriate doping according to other experimental investigations. However, the theoretical simulation and the intrinsic catalytic mechanism of CoS₂ remains insufficiently investigated. Therefore, in this study, density functional theory is used to investigate the HER catalytic activity of CoS₂ doped with a heteroatom. The results show that Pt-, N- and O-doped CoS₂ demonstrates smaller Gibbs free energies close to that of Pt, compared with the original CoS₂ and CoS₂ doped with other atoms. Furthermore, HER catalytic performance of CoS₂ can be improved by tuning d-band centers of H adsorption sites. This study provides an effective method to achieve modified CoS₂ for high-performance HER and to investigate other transition metal sulfides as HER electrode.