The effect of heteroatom doping on the active metal site of CoS(2) for hydrogen evolution reaction

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 CoS(2) in HER has been drawing more and more attention due to its low cost and relatively satisfactory HER catalytic performance. And CoS(2) 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 CoS(2) remains insufficiently investigated. Therefore, in this study, density functional theory is used to investigate the HER catalytic activity of CoS(2) doped with a heteroatom. The results show that Pt-, N- and O-doped CoS(2) demonstrates smaller Gibbs free energies close to that of Pt, compared with the original CoS(2) and CoS(2) doped with other atoms. Furthermore, HER catalytic performance of CoS(2) can be improved by tuning d-band centers of H adsorption sites. This study provides an effective method to achieve modified CoS(2) for high-performance HER and to investigate other transition metal sulfides as HER electrode.